{"id":1326,"date":"2025-09-26T14:37:47","date_gmt":"2025-09-26T06:37:47","guid":{"rendered":"https:\/\/eve2333.top\/?p=1326"},"modified":"2025-09-27T16:47:27","modified_gmt":"2025-09-27T08:47:27","slug":"%e6%89%8b%e5%86%99hashmap%ef%bc%88%e4%b8%8d%e5%90%ab%e7%ba%a2%e9%bb%91%e6%a0%91%ef%bc%89","status":"publish","type":"post","link":"https:\/\/eve2333.top\/?p=1326","title":{"rendered":"\u624b\u5199HashMap\uff08\u4e0d\u542b\u7ea2\u9ed1\u6811\uff09"},"content":{"rendered":"\n

\u597d\u7684\uff0c\u8fd9\u91cc\u662f\u4e00\u4e2a\u65b0\u7684\u5de5\u7a0b\u3002
\u4eca\u5929\u6211\u4eec\u5b9e\u73b0\u4e00\u4e2a\u54c8\u5e0cMap
\u6211\u4eec\u8fd9\u91cc\u53ea\u5b9e\u73b0\u4e09\u4e2a\u51fd\u6570\uff1aput<\/code>\u3001get<\/code> \u548c remove<\/code>\u3002<\/p>\n\n\n\n

\u6211\u4eec\u5148\u6765\u770b\u4e00\u4e0b\u8fd9\u4e09\u4e2a\u51fd\u6570\u7684\u5b9a\u4e49\u3002
\u6839\u636eJDK\u7684Map\u7684\u5b9a\u4e49\uff0cput<\/code>\u662f\u6709\u4e00\u4e2a\u8fd4\u56de\u503c\u7684\uff0c\u8fd4\u56de\u503c\u662f\u4e00\u4e2avalue\u3002
\u5b83\u7684\u610f\u601d\u662f\uff1a\u5982\u679c\u5f53\u524d\u7684Map\u91cc\u9762\u5df2\u7ecf\u6709\u4e86key\u5bf9\u5e94\u7684value\uff0c\u90a3\u4e48\u6211\u4eec\u5c31\u7528\u5f53\u524d\u4f20\u5165\u7684value\u53bb\u628a\u5b83\u8986\u76d6\u6389\uff0c\u540c\u65f6\u628a\u4e4b\u524d\u7684value\u8fd4\u56de\uff1b\u5982\u679c\u5f53\u524d\u7684HashMap\u91cc\u9762\u6ca1\u6709\u8fd9\u4e2akey\u5bf9\u5e94\u7684value\uff0c\u6211\u4eec\u5c31\u8fd4\u56denull\u3002
\u4e5f\u5c31\u662f\u8bf4\uff0c\u5982\u679c\u6211\u4eec\u4f20\u8fdb\u6765\u7684\u8fd9\u4e2akey\u548cvalue\u628a\u4e4b\u524dMap\u91cc\u7684key-value\u5bf9\u201c\u6324\u51fa\u53bb\u201d\u4e86\uff0c\u90a3\u4e48\u5c31\u628a\u88ab\u6324\u51fa\u7684value\u8fd4\u56de\uff1b\u5982\u679c\u6ca1\u6709\u88ab\u6324\u51fa\u53bb\uff08\u5373\u539f\u672c\u4e0d\u5b58\u5728\uff09\uff0c\u90a3\u4e48\u5c31\u8fd4\u56denull\u3002<\/p>\n\n\n\n

\u540c\u6837\u5730\uff0cremove<\/code>\u4e5f\u662f\u6709\u8fd4\u56de\u503c\u7684\uff1a
\u5982\u679c\u6211\u4eec\u5f53\u524d\u7684Map\u91cc\u9762\u6709\u8fd9\u4e2akey\u5bf9\u5e94\u7684value\uff0c\u90a3\u6211\u4eec\u5c31\u628a\u8fd9\u4e2avalue\u8fd4\u56de\uff1b\u5982\u679c\u6ca1\u6709\u8fd9\u4e2akey\u5bf9\u5e94\u7684value\uff0c\u6211\u4eec\u5c31\u76f4\u63a5\u8fd4\u56denull\u5c31\u53ef\u4ee5\u4e86\u3002<\/p>\n\n\n\n

\n\n\n\n

\u6211\u4eec\u6765\u601d\u8003\u4e00\u4e0b\uff1aMap\u5230\u5e95\u662f\u4ec0\u4e48\uff1f
Map\u662f\u4e00\u4e2a\u5bb9\u5668\uff0c\u5bb9\u5668\u91cc\u88c5\u7740\u4ec0\u4e48\uff1f
\u5bb9\u5668\u91cc\u88c5\u7740\u7684\u662fkey\u548cvalue\u3002
key\u548cvalue\u662f\u4e00\u5bf9\uff0c\u5b83\u4eec\u4e00\u5b9a\u662f\u6210\u5bf9\u51fa\u73b0\u7684\uff0c\u4e0d\u53ef\u80fd\u5355\u72ec\u5b58\u5728\u4e00\u4e2akey\u6216\u5355\u72ec\u4e00\u4e2avalue\u3002<\/p>\n\n\n\n

\u6240\u4ee5\u6211\u4eec\u7b2c\u4e00\u6b65\u5e94\u8be5\u628akey\u548cvalue\u5173\u8054\u8d77\u6765\u3002
\u90a3\u4e48\u6211\u4eec\u600e\u4e48\u6837\u628akey\u548cvalue\u5173\u8054\u8d77\u6765\u5462\uff1f<\/p>\n\n\n\n

\u6211\u4eec\u53ef\u4ee5\u5199\u4e00\u4e2a\u7c7b\uff0c\u53eb\u505aNode<\/code>\uff08\u5f53\u7136\u8fd9\u4e2a\u540d\u5b57\u53ef\u4ee5\u4efb\u610f\u53d6\uff0c\u6211\u8fd9\u8fb9\u5148\u53eb\u5b83Node<\/code>\uff09\u3002
\u8fd9\u4e2aNode<\/code>\u5e94\u8be5\u6709\u4ec0\u4e48\u6210\u5458\u53d8\u91cf\u5462\uff1f
\u5b83\u5e94\u8be5\u6709\u4e00\u4e2akey<\/code>\uff0c\u4e5f\u5e94\u8be5\u6709\u4e00\u4e2avalue<\/code>\u3002
\u5f53\u5b83\u5b58\u4e86\u4e00\u4e2akey\u548c\u4e00\u4e2avalue\u4e4b\u540e\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u76f4\u63a5\u64cd\u4f5c\u8fd9\u4e2anode\uff0c\u800c\u4e0d\u9700\u8981\u72ec\u7acb\u5730\u5bf9key\u548cvalue\u8fdb\u884c\u64cd\u4f5c\u3002
\u6211\u4eec\u628akey\u548cvalue\u7ec4\u5408\u5728\u4e00\u8d77\u2014\u2014\u8fd9\u4e2aNode<\/code>\u5c31\u662f\u88c5\u7740\u4e00\u5bf9key-value\u7684\u5bb9\u5668\u3002
\u800c\u6574\u4e2aMap\uff0c\u5219\u662f\u88c5\u7740\u4e00\u5927\u5806\u8fd9\u6837\u7684Node<\/code>\u7684\u5bb9\u5668\u3002<\/p>\n\n\n\n

\u73b0\u5728\u6211\u4eec\u901a\u8fc7\u4e00\u4e2aNode<\/code>\u7c7b\uff0c\u6210\u529f\u5730\u628a\u4f20\u8fdb\u6765\u7684key\u548cvalue\u5173\u8054\u4e86\u8d77\u6765\u3002<\/p>\n\n\n\n

\u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u9700\u8981\u4e00\u4e2a\u5bb9\u5668\u628a\u8fd9\u4e9bNode<\/code>\u88c5\u8d77\u6765\u3002
\u4e3a\u4ec0\u4e48\uff1f\u56e0\u4e3a\u6211\u4eec\u5728\u540e\u7eed\u8c03\u7528get<\/code>\u7684\u65f6\u5019\u9700\u8981\u80fd\u591f\u627e\u5230\u8fd9\u4e9b\u8282\u70b9\u3002<\/p>\n\n\n\n

\u8bf4\u5230\u5bb9\u5668\uff0c\u6211\u4eec\u81ea\u7136\u800c\u7136\u5c31\u60f3\u5230\u4e86\u6570\u7ec4\u3002
\u4e8e\u662f\u6211\u4eec\u53ef\u4ee5\u5728\u8fd9\u5b9a\u4e49\u4e00\u4e2a\u6570\u7ec4\uff1aNode[]<\/code>\uff0c\u6211\u4eec\u628a\u5b83\u53eb\u505atable<\/code>\u3002
\u90a3\u4e48\u8fd9\u4e2a\u6570\u7ec4\u6211\u4eec\u5b9a\u4e49\u591a\u957f\u5462\uff1f\u6211\u4eec\u5148\u968f\u4fbf\u5199\u4e00\u4e2a10\u3002<\/p>\n\n\n\n

\u4f46\u968f\u7740\u4e0d\u65ad\u5730put<\/code>\u64cd\u4f5c\uff0c\u6211\u4eec\u7684\u6570\u636e\u4f1a\u8d8a\u6765\u8d8a\u591a\uff0c\u6570\u7ec4\u5c31\u9700\u8981\u52a8\u6001\u6269\u5bb9\u3002
\u6211\u4eec\u77e5\u9053JDK\u4e2d\u7684ArrayList<\/code>\u672c\u8d28\u4e0a\u5c31\u662f\u4e00\u4e2a\u52a8\u6001\u6570\u7ec4\u3002
\u6240\u4ee5\u4e3a\u4e86\u7b80\u5316\u5b9e\u73b0\uff0c\u6211\u4eec\u6682\u65f6\u5148\u7528ArrayList<Node><\/code>\u6765\u66ff\u4ee3\u6570\u7ec4\uff0c\u4e5f\u53eb\u505atable<\/code>\uff1a<\/p>\n\n\n\n

List<Node> table = new ArrayList<>();<\/code><\/pre>\n\n\n\n
OK\uff0c\u6211\u4eec\u73b0\u5728\u7528\u8fd9\u4e2aArrayList<\/code>\u6765\u4ee3\u66ff\u56fa\u5b9a\u957f\u5ea6\u7684\u6570\u7ec4\u3002<\/p>\n\n\n\n
public class MyHashMap<K, V> {\n    List<Node<K, V>> table = new ArrayList<>();\n\n    public V put(K key, V value) {\n        return null;\n    }\n\n    public V get(K key) {\n        return null;\n    }\n\n    public V remove(K key) {\n        return null;\n    }\n\n    class Node<K, V> {\n        K key;\n        V value;\n\n        public Node(K key, V value) {\n            this.key = key;\n            this.value = value;\n        }\n    }\n}<\/code><\/pre>\n\n\n\n
\n\n\n\n
\u73b0\u5728\u6211\u4eec\u5f00\u59cb\u586b\u5145\u8fd9\u4e09\u4e2a\u6838\u5fc3\u51fd\u6570\u3002<\/p>\n\n\n\n
\u7b2c\u4e00\u6b65\uff1a\u5b9e\u73b0 put<\/code><\/h3>\n\n\n\n
\u5728put<\/code>\u7684\u65f6\u5019\uff0c\u6211\u4eec\u9996\u5148\u8981\u77e5\u9053\u5f53\u524d\u8fd9\u4e2atable<\/code>\u91cc\u9762\u6709\u6ca1\u6709\u6211\u4eec\u8fd9\u4e2akey\u3002
\u5982\u679c\u6709\uff0c\u53ea\u9700\u8981\u628a\u8fd9\u4e2avalue\u6539\u6210\u65b0\u7684value\u5373\u53ef\uff1b\u5982\u679c\u6ca1\u6709\uff0c\u5c31\u9700\u8981\u5411table<\/code>\u4e2d\u65b0\u589e\u4e00\u4e2aNode<\/code>\u3002<\/p>\n\n\n\n
\u597d\u7684\uff0c\u7b2c\u4e00\u6b65\uff1a\u68c0\u67e5\u5f53\u524dtable<\/code>\u4e2d\u662f\u5426\u5df2\u6709\u8be5key\u3002<\/p>\n\n\n\n
\u6211\u4eec\u53ef\u4ee5\u904d\u5386\u4e00\u4e0b\u8fd9\u4e2atable<\/code>\uff1a
\u5bf9\u4e8e\u6bcf\u4e00\u4e2aNode<\/code>\uff0c\u5982\u679c\u5b83\u7684key<\/code>\u548c\u6211\u4eec\u8981\u63d2\u5165\u7684key\u76f8\u540c\uff0c\u8bf4\u660e\u5df2\u7ecf\u5b58\u5728\uff0c\u6211\u4eec\u5c31\u5c06\u5b83\u7684value<\/code>\u66f4\u65b0\u4e3a\u65b0\u503c\uff0c\u5e76\u8fd4\u56de\u65e7\u7684value\u3002<\/p>\n\n\n\n
\u4f46\u662f\u6ce8\u610f\u4e00\u70b9\uff1a\u5982\u679c\u539f\u6765\u7684table<\/code>\u4e2d\u5df2\u7ecf\u5b58\u5728\u8fd9\u4e2akey\uff0c\u90a3\u4e48\u6211\u4eec\u8981\u628a\u65e7\u7684value\u8fd4\u56de\u56de\u53bb\u3002<\/p>\n\n\n\n
\u6240\u4ee5\u6211\u4eec\u5728\u8fd9\u91cc\u9700\u8981\u8bb0\u5f55\u4e00\u4e0b\u65e7\u7684value\uff1a<\/p>\n\n\n\n
V oldValue = node.value;\nnode.value = value;\nreturn oldValue;<\/code><\/pre>\n\n\n\n
\u5982\u679c\u904d\u5386\u7ed3\u675f\u90fd\u6ca1\u6709\u627e\u5230\u5339\u914d\u7684key\uff0c\u8bf4\u660e\u539f\u6765\u4e0d\u5b58\u5728\uff0c\u6211\u4eec\u5c31\u9700\u8981\u521b\u5efa\u4e00\u4e2a\u65b0\u7684Node<\/code>\u5bf9\u8c61\uff1a<\/p>\n\n\n\n
Node newNode = new Node(key, value);\ntable.add(newNode);\nreturn null; \/\/ \u8868\u793a\u4e4b\u524d\u6ca1\u6709\u8fd9\u4e2akey<\/code><\/pre>\n\n\n\n
\u8fd9\u6837\uff0cput<\/code>\u51fd\u6570\u5c31\u5199\u5b8c\u4e86\u3002<\/p>\n\n\n\n
public V put(K key, V value) {\n    for (Node<K, V> kvNode = table) {\n        if (kvNode.key.equals(key)) {\n            V oldValue = kvNode.value;\n            kvNode.value = value;\n            return oldValue;\n        }\n    }\n    Node<K, V> newNode = new Node<>(key, value);\n    table.add(newNode);\n    return null;\n}<\/code><\/pre>\n\n\n\n
\n\n\n\n
\u7b2c\u4e8c\u6b65\uff1a\u5b9e\u73b0 get<\/code><\/h3>\n\n\n\n
get<\/code>\u7684\u64cd\u4f5c\u903b\u8f91\u5176\u5b9e\u548c\u4e0a\u9762\u904d\u5386\u7684\u903b\u8f91\u662f\u4e00\u6837\u7684\u3002
\u6211\u4eec\u76f4\u63a5\u590d\u7528\u521a\u624d\u7684\u601d\u8def\uff1a<\/p>\n\n\n\n
\u904d\u5386table<\/code>\u4e2d\u7684\u6bcf\u4e2aNode<\/code>\uff0c\u5224\u65ad\u5176key<\/code>\u662f\u5426\u4e0e\u4f20\u5165\u7684key\u76f8\u7b49\u3002
\u5982\u679c\u76f8\u7b49\uff0c\u5c31\u76f4\u63a5\u8fd4\u56de\u8fd9\u4e2aNode<\/code>\u7684value<\/code>\u3002<\/p>\n\n\n\n
\u5982\u679c\u904d\u5386\u5b8c\u90fd\u6ca1\u6709\u627e\u5230\uff0c\u5c31\u8fd4\u56denull<\/code>\u3002<\/p>\n\n\n\n
\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n\n\n\n
for (Node node : table) {\n    if (node.key.equals(key)) {\n        return node.value;\n    }\n}\nreturn null;<\/code><\/pre>\n\n\n\n
\n\n\n\n
\u7b2c\u4e09\u6b65\uff1a\u5b9e\u73b0 remove<\/code><\/h3>\n\n\n\n
remove<\/code>\u4e5f\u662f\u7c7b\u4f3c\u7684\u9053\u7406\u3002
\u6211\u4eec\u9700\u8981\u4ece\u6570\u7ec4\u4e2d\u627e\u5230\u90a3\u4e2akey<\/code>\u4e0e\u4f20\u5165key\u76f8\u540c\u7684Node<\/code>\u3002<\/p>\n\n\n\n
\u4f46\u8fd9\u4e00\u6b21\u6211\u4eec\u4e0d\u80fd\u53ea\u62ff\u5230Node<\/code>\u672c\u8eab\uff0c\u8fd8\u9700\u8981\u77e5\u9053\u5b83\u7684\u7d22\u5f15\uff08\u89d2\u6807\uff09\uff0c\u56e0\u4e3a\u6211\u4eec\u662f\u8981\u4eceArrayList<\/code>\u4e2d\u79fb\u9664\u5b83\u3002<\/p>\n\n\n\n
\u4e8e\u662f\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528table.size()<\/code>\u6765\u4f5c\u4e3a\u5faa\u73af\u6761\u4ef6\uff0c\u901a\u8fc7table.get(i)<\/code>\u9010\u4e2a\u8bbf\u95ee\u5143\u7d20\uff1a<\/p>\n\n\n\n
for (int i = 0; i < table.size(); i++) {\n    Node node = table.get(i);\n    if (node.key.equals(key)) {\n        \/\/ \u627e\u5230\u4e86\uff0c\u6267\u884c remove \u64cd\u4f5c\n        Node removedNode = table.remove(i); \/\/ remove \u8fd4\u56de\u88ab\u5220\u9664\u7684\u5143\u7d20\n        return removedNode.value;\n    }\n}\nreturn null;<\/code><\/pre>\n\n\n\n
\u8fd9\u91cc\u8865\u5145\u4e00\u70b9\u5173\u4e8eArrayList<\/code>\u7684remove<\/code>\u673a\u5236\u7684\u77e5\u8bc6\u3002<\/p>\n\n\n\n
\u5047\u8bbe\u6211\u4eec\u6709\u4e00\u4e2a\u957f\u5ea6\u4e3a5\u7684\u6570\u7ec4\uff1a[1, 2, 3, 4, 5]<\/code>\uff0c\u521d\u59cb\u65f6\u540e\u9762\u90fd\u662fnull<\/code>\u3002
\u4f46\u5b9e\u9645\u4e0aArrayList<\/code>\u5185\u90e8\u7ef4\u62a4\u4e86\u4e00\u4e2asize<\/code>\u5b57\u6bb5\uff0c\u8868\u793a\u5f53\u524d\u6709\u6548\u5143\u7d20\u7684\u6570\u91cf\u3002<\/p>\n\n\n\n
\u6bd4\u5982\u6211\u4eec\u53ea\u6dfb\u52a0\u4e86\u4e09\u4e2a\u5143\u7d20 [1, 2, 3]<\/code>\uff0c\u90a3\u4e48\u867d\u7136\u5e95\u5c42\u6570\u7ec4\u957f\u5ea6\u53ef\u80fd\u662f5\uff0c\u4f46size=3<\/code>\uff0c\u53ea\u6709\u524d\u4e09\u4e2a\u4f4d\u7f6e\u662f\u53ef\u8bbf\u95ee\u7684\u3002\u8fd9\u5c31\u662fArrayList<\/code>\u7684\u672c\u8d28\u3002<\/p>\n\n\n\n
\u5f53\u6211\u4eec\u8c03\u7528remove(1)<\/code>\uff08\u4e5f\u5c31\u662f\u5220\u9664\u503c\u4e3a2\u7684\u90a3\u4e2a\u5143\u7d20\uff09\u65f6\uff0c\u4e0d\u4ec5\u4ec5\u662f\u628a\u90a3\u4e2a\u4f4d\u7f6e\u8bbe\u4e3anull<\/code>\u90a3\u4e48\u7b80\u5355\uff0c\u800c\u662f\u8981\u628a\u540e\u9762\u7684\u6bcf\u4e00\u4e2a\u5143\u7d20\u90fd\u5f80\u524d\u79fb\u52a8\u4e00\u4f4d\uff1a<\/p>\n\n\n\n
\u539f\u6570\u7ec4\uff1a[1, 2, 3, 4, null]<\/code> \u2192 \u5220\u9664\u540e\u53d8\u6210 [1, 3, 4, 4, null]<\/code>\uff0c\u7136\u540esize--<\/code>\u53d8\u4e3a2\u3002<\/p>\n\n\n\n
\u4e0d\u8fc7\u8fd8\u6709\u4e00\u4e2a\u5c0f\u6280\u5de7\uff1a\u53ea\u8981size<\/code>\u6539\u5c0f\u4e86\uff0csize<\/code>\u4e4b\u540e\u7684\u5143\u7d20\u5373\u4f7f\u4e0d\u7f6e\u4e3anull<\/code>\u4e5f\u6ca1\u5173\u7cfb\uff0c\u56e0\u4e3a\u6211\u4eec\u53ea\u80fd\u8bbf\u95ee\u524dsize<\/code>\u4e2a\u5143\u7d20\u3002<\/p>\n\n\n\n
\u4e3e\u4e2a\u4f8b\u5b50\uff1a\u6570\u7ec4\u662f [1, 2, 3, 4, null]<\/code>\uff0csize=4<\/code>\u3002
\u5982\u679c\u6211\u4eec\u5220\u9664index=1\u7684\u5143\u7d20\uff08\u53732\uff09\uff0c\u5219\uff1a<\/p>\n\n\n\n
    \n
  • \u628aindex=2\u7684\u5143\u7d20\uff083\uff09\u79fb\u5230index=1\uff1b<\/li>\n\n\n\n
  • \u628aindex=3\u7684\u5143\u7d20\uff084\uff09\u79fb\u5230index=2\uff1b<\/li>\n\n\n\n
  • \u6700\u540esize--<\/code>\u53d8\u62103\u3002<\/li>\n<\/ul>\n\n\n\n
    \u6b64\u65f6index=3\u7684\u4f4d\u7f6e\u662f\u5426\u4e3anull<\/code>\u65e0\u6240\u8c13\uff0c\u56e0\u4e3a\u8d85\u51fasize<\/code>\u7684\u90e8\u5206\u4e0d\u4f1a\u88ab\u8bbf\u95ee\u3002<\/p>\n\n\n\n
    \u8fd9\u90e8\u5206\u5173\u4e8e\u52a8\u6001\u6570\u7ec4\u7684\u79fb\u52a8\u7ec6\u8282\uff0c\u6211\u4eec\u4e4b\u540e\u53ef\u4ee5\u5728\u624b\u5199ArrayList<\/code>\u7684\u89c6\u9891\u4e2d\u8be6\u7ec6\u5c55\u5f00\u3002
    \u8fd9\u91cc\u53ea\u662f\u7a0d\u5fae\u63d0\u4e00\u4e0b\u3002<\/p>\n\n\n\n
    \n\n\n\n
    \u73b0\u5728\u56de\u5230\u6211\u4eec\u7684remove<\/code>\u5b9e\u73b0\uff1a<\/p>\n\n\n\n
    \u6211\u4eec\u901a\u8fc7\u7d22\u5f15i\u627e\u5230\u76ee\u6807\u8282\u70b9\uff0c\u8c03\u7528table.remove(i)<\/code>\uff0c\u8fd9\u4e2a\u65b9\u6cd5\u4f1a\u8fd4\u56de\u88ab\u79fb\u9664\u7684Node<\/code>\uff0c\u7136\u540e\u6211\u4eec\u8fd4\u56de\u5b83\u7684value<\/code>\u5373\u53ef\u3002<\/p>\n\n\n\n
    OK\uff0cremove<\/code>\u5b8c\u6210\u3002<\/p>\n\n\n\n
    public V remove(K key) {\n    for (int i = 0; i < table.size(); i++) {\n        Node<K, V> kvNode = table.get(i);\n        if (kvNode.key.equals(key)) {\n            Node<K, V> removedNode = this.table.remove(i);\n            return removedNode.value;\n        }\n    }\n    return null;\n}<\/code><\/pre>\n\n\n\n
    \n\n\n\n
    \u5199\u5b8c\u8fd9\u4e09\u4e2a\u51fd\u6570\u4e4b\u540e\uff0c\u6211\u4eec\u5e94\u8be5\u518d\u7ed9\u6211\u4eec\u7684HashMap\u63d0\u4f9b\u4e00\u4e2a\u67e5\u8be2\u5f53\u524d\u952e\u503c\u5bf9\u6570\u91cf\u7684\u529f\u80fd\u3002
    \u4e5f\u5c31\u662f\u8bf4\uff0c\u589e\u52a0\u4e00\u4e2a\u8fd4\u56deint<\/code>\u7c7b\u578b\u7684\u51fd\u6570\uff0c\u53eb\u505asize()<\/code>\u3002<\/p>\n\n\n\n
    \u8fd9\u4e2a\u51fd\u6570\u5f88\u7b80\u5355\uff0c\u76f4\u63a5\u8fd4\u56de\u5f53\u524dtable<\/code>\u7684size()<\/code>\u5373\u53ef\uff1a<\/p>\n\n\n\n
    public int size() {\n    return table.size();\n}<\/code><\/pre>\n\n\n\n
    \u8fd9\u6837\u6211\u4eec\u5c31\u5bf9\u5916\u63d0\u4f9b\u4e86\u4e00\u4e2aAPI\uff0c\u53ef\u4ee5\u8ba9\u5916\u90e8\u77e5\u9053\u5f53\u524dHashMap\u4e2d\u6709\u591a\u5c11\u4e2a\u952e\u503c\u5bf9\u3002<\/p>\n\n\n\n
    \n\n\n\n
    \u4e3a\u4e86\u9a8c\u8bc1\u6b63\u786e\u6027\uff0c\u6211\u5199\u4e86\u4e00\u4e2a\u6d4b\u8bd5\u7528\u4f8b\u3002
    \u6211\u4eec\u5148\u770b\u4e00\u4e0b\u8fd9\u6bb5\u4ee3\u7801\uff1a<\/p>\n\n\n\n
    class MyHashMapTest {\n    @Test\n    void testApi() {\n        MyHashMap<String, String> myHashMap = new MyHashMap<>();\n        int count = 10;\n        for (int i = 0; i < count; i++) {\n            myHashMap.put(String.valueOf(i), String.valueOf(i));\n        }\n\n        assertEquals(expected: 10, myHashMap.size());\n\n        for (int i = 0; i < count; i++) {\n            assertEquals(String.valueOf(i), myHashMap.get(String.valueOf(i)));\n        }\n\n        myHashMap.remove(\"8\");\n        assertNull(myHashMap.get(\"8\"));\n\n        assertEquals(expected: count - 1, myHashMap.size());\n    }\n}<\/code><\/pre>\n\n\n\n
    \u5982\u679c\u8fd9\u4e2a\u6d4b\u8bd5\u901a\u8fc7\u4e86\uff0c\u8bf4\u660e\u6211\u4eec\u7684\u4ee3\u7801\u57fa\u672c\u662f\u6b63\u786e\u7684\u3002<\/p>\n\n\n\n
    \n
    \u6211\u4eec\u8fd0\u884c\u4e00\u4e0b\u6d4b\u8bd5\u2026\u2026\u53d1\u73b0\u51fa\u4e86\u95ee\u9898\uff01<\/s><\/p>\n\n\n\n
    \n
    \u62a5\u9519\u63d0\u793a\u662fremove\u5931\u8d25\u4e86\u3002
    \u6211\u4eec\u70b9\u8fdb\u53bb\u770bremove\u65b9\u6cd5\uff1a<\/s><\/p>\n\n\n\n
    \u53d1\u73b0\u95ee\u9898\u51fa\u5728\u8fd9\u91cc\uff1a\u6211\u4eec\u5199\u4e86 node.equals(key)\uff0c\u4f46\u5b9e\u9645\u4e0a\u5e94\u8be5\u662f node.key.equals(key)\uff01<\/s><\/p>\n\n\n\n
    \u6211\u4eec\u6bd4\u8f83\u7684\u662fNode\u7684key\u548c\u4f20\u5165\u7684key\u662f\u5426\u76f8\u7b49\uff0c\u800c\u4e0d\u662f\u62ff\u6574\u4e2aNode\u53bb\u548ckey\u6bd4\u8f83\u3002<\/s><\/p>\n<\/div><\/div>\n\u4e8b\u5b9e\u4e0a\u65e9\u5df2\u7ecf\u4fee\u6539\u4e86<\/strong><\/cite><\/blockquote>\n\n\n\n
    \u4fee\u6539\u4e3a\uff1a<\/p>\n\n\n\n
    if (node.key.equals(key))<\/code><\/pre>\n\n\n\n
    \u7136\u540e\u518d\u91cd\u65b0\u8dd1\u6d4b\u8bd5\u2014\u2014OK\uff0c\u8fd9\u6b21\u901a\u8fc7\u4e86\uff01<\/p>\n\n\n\n
    \u8bf4\u660e\u6211\u4eec\u7684\u57fa\u7840\u903b\u8f91\u662f\u6ca1\u6709\u95ee\u9898\u7684\u3002<\/p>\n\n\n\n
    \n\n\n\n
    \u73b0\u5728\u6211\u4eec\u628acount<\/code>\u6539\u62101\u4e07\uff1a<\/p>\n\n\n\n
    int count = 10000;<\/code><\/pre>\n\n\n\n
    \u518d\u8dd1\u4e00\u6b21\u6d4b\u8bd5\u2014\u2014\u4ecd\u7136\u80fd\u901a\u8fc7\uff0c\u4f46\u660e\u663e\u53d8\u6162\u4e86\u3002<\/p>\n\n\n\n
    \u6211\u4eec\u518d\u52a0\u4e00\u4e2a\u6570\u91cf\u7ea7\uff0c\u53d8\u621010\u4e07\uff1a<\/p>\n\n\n\n
    int count = 100000;<\/code><\/pre>\n\n\n\n
    \u8fd9\u6b21\u6267\u884c\u6548\u7387\u975e\u5e38\u5dee\uff0c\u751a\u81f3\u957f\u65f6\u95f4\u65e0\u6cd5\u7ed3\u675f\u3002<\/p>\n\n\n\n
    \u6211\u4eec\u624b\u52a8\u7ec8\u6b62\u7a0b\u5e8f\u3002<\/p>\n\n\n\n
    \u8fd9\u8bf4\u660e\u6211\u4eec\u7684\u6027\u80fd\u5b58\u5728\u4e25\u91cd\u95ee\u9898\u3002<\/p>\n\n\n\n
    \u6211\u4eec\u91cd\u65b0\u5ba1\u89c6\u4e00\u4e0b\u903b\u8f91\uff1a<\/p>\n\n\n\n
    \u6bcf\u6b21put<\/code>\u65f6\u90fd\u9700\u8981\u904d\u5386\u6574\u4e2atable<\/code>\uff0c\u4ee5\u67e5\u627e\u662f\u5426\u5b58\u5728\u76f8\u540c\u7684key\u3002
    \u8fd9\u610f\u5473\u7740put<\/code>\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u662fO(n)\uff0c\u5176\u4e2dn\u662f\u5f53\u524dtable<\/code>\u4e2d\u5143\u7d20\u7684\u4e2a\u6570\u3002<\/p>\n\n\n\n
    \u540c\u7406\uff0cget<\/code>\u548cremove<\/code>\u4e5f\u90fd\u9700\u8981\u904d\u5386\uff0c\u65f6\u95f4\u590d\u6742\u5ea6\u4e5f\u662fO(n)\u3002<\/p>\n\n\n\n
    \u800c\u4e14\uff0c\u8fd9\u4e2a\u7c7b\u660e\u660e\u53eb\u201cHashMap\u201d\uff0c\u5374\u548c\u201c\u54c8\u5e0c\u201d\u6ca1\u6709\u4efb\u4f55\u5173\u7cfb\uff01
    \u6211\u4eec\u5e94\u8be5\u53eb\u5b83ArrayMap<\/code>\u66f4\u5408\u9002\u4e00\u4e9b\u3002<\/p>\n\n\n\n
    \u771f\u6b63\u7684HashMap\u5e94\u8be5\u5229\u7528\u6570\u7ec4\u652f\u6301\u968f\u673a\u8bbf\u95ee\uff08Random Access\uff09\u7684\u7279\u6027\uff1a
    \u5982\u679c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7key\u5feb\u901f\u8ba1\u7b97\u51fa\u5b83\u5728\u6570\u7ec4\u4e2d\u7684\u4f4d\u7f6e\uff08\u89d2\u6807\uff09\uff0c\u5c31\u4e0d\u9700\u8981\u904d\u5386\u6574\u4e2a\u6570\u7ec4\u4e86\u3002<\/p>\n\n\n\n
    \n\n\n\n
    \u5982\u4f55\u505a\u5230\u8fd9\u4e00\u70b9\uff1f<\/p>\n\n\n\n
    \u6211\u4eec\u53ef\u4ee5\u4f7f\u7528key\u7684hashCode()<\/code>\u6765\u51b3\u5b9a\u5b83\u5728table<\/code>\u4e2d\u7684\u5b58\u653e\u4f4d\u7f6e\u3002<\/p>\n\n\n\n
    \u4f8b\u5982\uff0c\u5047\u8bbe\u5f53\u524d\u6570\u7ec4\u957f\u5ea6\u662f10\uff0c\u67d0\u4e2akey\u7684hashCode()<\/code>\u662f11\uff0c
    \u6211\u4eec\u7528 11 % 10 = 1<\/code> \u5f97\u5230\u4f59\u65701\uff0c\u4e8e\u662f\u5c31\u628a\u8fd9\u4e2akey-value\u653e\u5230\u6570\u7ec4\u4e0b\u6807\u4e3a1\u7684\u4f4d\u7f6e\u3002<\/p>\n\n\n\n
    \u8fd9\u5c31\u662f\u54c8\u5e0c\u51fd\u6570\u7684\u57fa\u672c\u601d\u60f3\uff1a\u901a\u8fc7\u54c8\u5e0c\u503c\u5b9a\u4f4d\u5b58\u50a8\u4f4d\u7f6e<\/strong>\u3002<\/p>\n\n\n\n
    \u4f46\u8fd9\u91cc\u6709\u4e2a\u95ee\u9898\uff1a\u4e0d\u540c\u7684key\u53ef\u80fd\u4ea7\u751f\u76f8\u540c\u7684\u4f59\u6570\uff0c\u6bd4\u5982\uff1a<\/p>\n\n\n\n
      \n
    • hashCode=11 \u2192 11 % 10 = 1<\/li>\n\n\n\n
    • hashCode=21 \u2192 21 % 10 = 1<\/li>\n\n\n\n
    • hashCode=31 \u2192 31 % 10 = 1<\/li>\n<\/ul>\n\n\n\n
      \u8fd9\u5c31\u4ea7\u751f\u4e86\u54c8\u5e0c\u51b2\u7a81<\/strong>\u3002<\/p>\n\n\n\n
      \u4f60\u53ef\u80fd\u4f1a\u60f3\uff1a\u90a3\u6211\u4eec\u628a\u6570\u7ec4\u5f04\u5f97\u5f88\u5927\u4e0d\u5c31\u884c\u4e86\uff1f\u6bd4\u5982\u957f\u5ea650\u3001100\uff1f<\/p>\n\n\n\n
      \u4f46\u8fd9\u4e0d\u53ef\u9760\uff0c\u539f\u56e0\u6709\u4e24\u4e2a\uff1a<\/p>\n\n\n\n
        \n
      1. hashCode()<\/code>\u672c\u8eab\u662fint\u7c7b\u578b\uff0832\u4f4d\uff09\uff0c\u6700\u5927\u7ea642\u4ebf\u79cd\u4e0d\u540c\u503c\uff0c\u4f46\u5bf9\u8c61\u662f\u65e0\u9650\u7684\uff0c\u6839\u636e\u9e3d\u5de2\u539f\u7406\uff0c\u5fc5\u7136\u4f1a\u51fa\u73b0\u51b2\u7a81\u3002<\/li>\n\n\n\n
      2. \u5373\u4f7f\u5bb9\u91cf\u8db3\u591f\u5927\uff0c\u4e5f\u65e0\u6cd5\u907f\u514d\u4e0d\u540c\u5bf9\u8c61hashCode()<\/code>\u76f8\u540c\u7684\u60c5\u51b5\uff08\u5982\u5b57\u7b26\u4e32\"FB\"\u548c\"EA\"\u7684hashCode()<\/code>\u53ef\u80fd\u76f8\u540c\uff09\u3002<\/li>\n<\/ol>\n\n\n\n
        \u56e0\u6b64\uff0c\u9760\u6269\u5927\u6570\u7ec4\u5bb9\u91cf\u6765\u89e3\u51b3\u51b2\u7a81\u662f\u4e0d\u53ef\u884c\u7684\u3002<\/p>\n\n\n\n
        \u6211\u4eec\u9700\u8981\u4e00\u79cd\u5904\u7406\u51b2\u7a81\u7684\u65b9\u6cd5\u2014\u2014\u62c9\u94fe\u6cd5\uff08Separate Chaining\uff09<\/strong>\u3002<\/p>\n\n\n\n
        \n\n\n\n
        \u4e0b\u9762\u6211\u7528\u4e00\u4e2a\u52a8\u753b\u6765\u89e3\u91ca\u4ec0\u4e48\u662f\u62c9\u94fe\u6cd5\uff1a<\/p>\n\n\n\n
        \u60f3\u8c61\u4e00\u4e2a\u957f\u5ea6\u4e3a10\u7684\u6570\u7ec4\uff0c\u89d2\u6807\u4ece0\u52309\u3002<\/p>\n\n\n\n
        \u6765\u4e86\u4e00\u4e2akey=\"Tom\"\uff0c\u5b83\u7684hashCode()<\/code>\u7ecf\u8fc7\u53d6\u6a21\u8fd0\u7b97\u540e\u5f97\u52301\uff0c\u4e8e\u662f\u653e\u5728table[1]<\/code>\u3002<\/p>\n\n\n\n
        \u63a5\u7740key=\"Jerry\"\uff0c\u8ba1\u7b97\u5f97\u89d2\u6807\u4e3a2\uff0c\u653e\u5728table[2]<\/code>\u3002<\/p>\n\n\n\n
        \u518d\u6765\u4e00\u4e2akey=\"Leo\"\uff0c\u5b83\u7684\u54c8\u5e0c\u53d6\u6a21\u7ed3\u679c\u4e5f\u662f1\uff0c\u53d1\u751f\u51b2\u7a81\u3002<\/p>\n\n\n\n
        \u8fd9\u65f6\u6211\u4eec\u4e0d\u518d\u8986\u76d6\uff0c\u800c\u662f\u8ba9table[1]<\/code>\u6210\u4e3a\u4e00\u4e2a\u94fe\u8868\u5934\uff0c\u628a\"Tom\"\u548c\"Leo\"\u4e32\u6210\u4e00\u4e2a\u94fe\u8868\u3002<\/p>\n\n\n\n
        \u67e5\u627e\u65f6\uff0c\u5148\u7b97\u51fa\u89d2\u68071\uff0c\u518d\u6cbf\u7740\u94fe\u8868\u4f9d\u6b21\u6bd4\u8f83key\uff0c\u76f4\u5230\u627e\u5230\u5339\u914d\u9879\u3002<\/p>\n\n\n\n
        \u8fd9\u79cd\u65b9\u5f0f\u5c31\u662f\u62c9\u94fe\u6cd5<\/strong>\uff1a\u6bcf\u4e2a\u6570\u7ec4\u4f4d\u7f6e\u6302\u4e00\u4e2a\u94fe\u8868\uff0c\u7528\u6765\u5b58\u50a8\u6240\u6709\u54c8\u5e0c\u5230\u8be5\u4f4d\u7f6e\u7684\u952e\u503c\u5bf9\u3002<\/p>\n\n\n\n
        \"\"<\/figure>\n\n\n\n
        \n\n\n\n
        \u6211\u4eec\u56de\u5230\u4ee3\u7801\uff0c\u5b9e\u73b0\u8fd9\u4e2a\u601d\u8def\u3002<\/p>\n\n\n\n
        \u9996\u5148\uff0ctable<\/code>\u4e0d\u518d\u9700\u8981\u7528ArrayList<Node><\/code>\u4e86\uff0c\u800c\u662f\u6539\u4e3a\u771f\u6b63\u7684\u6570\u7ec4\uff1a<\/p>\n\n\n\n
        Node[] table;<\/code><\/pre>\n\n\n\n
        \u521d\u59cb\u5316\u65f6\u521b\u5efa\u4e00\u4e2aNode\u6570\u7ec4\uff1a<\/p>\n\n\n\n
        table = new Node[10]; \/\/ \u521d\u59cb\u957f\u5ea6\u8bbe\u4e3a10<\/code><\/pre>\n\n\n\n
        \u7136\u540e\u6211\u4eec\u91cd\u5199put<\/code>\u65b9\u6cd5\u3002<\/p>\n\n\n\n
        \n\n\n\n
        \u5728put<\/code>\u4e4b\u524d\uff0c\u6211\u4eec\u9700\u8981\u4e00\u4e2a\u8f85\u52a9\u51fd\u6570\uff0c\u7528\u6765\u8ba1\u7b97key\u5bf9\u5e94\u5728\u6570\u7ec4\u4e2d\u7684\u89d2\u6807\uff1a<\/p>\n\n\n\n
        private int indexOf(Object key) {\n    return Math.abs(key.hashCode()) % table.length;\n}<\/code><\/pre>\n\n\n\n
        \u6ce8\u610f\uff1ahashCode()<\/code>\u53ef\u80fd\u662f\u8d1f\u6570\uff0c\u6240\u4ee5\u53d6\u7edd\u5bf9\u503c\u3002<\/p>\n\n\n\n
        \u62ff\u5230\u89d2\u6807\u540e\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u5b9a\u4f4d\u5230table[index]<\/code>\uff0c\u4e5f\u5c31\u662f\u94fe\u8868\u7684\u5934\u8282\u70b9\u3002<\/p>\n\n\n\n
        \u5982\u679c\u5934\u8282\u70b9\u4e3a\u7a7a\uff08null\uff09\uff0c\u8bf4\u660e\u5f53\u524d\u4f4d\u7f6e\u8fd8\u6ca1\u6709\u4efb\u4f55\u5143\u7d20\uff0c\u6211\u4eec\u76f4\u63a5\u521b\u5efa\u65b0\u8282\u70b9\u653e\u4e0a\u53bb\uff1a<\/p>\n\n\n\n
        int index = indexOf(key);\nif (table[index] == null) {\n    table[index] = new Node(key, value);\n    return null;\n}<\/code><\/pre>\n\n\n\n
        \u4f46\u5982\u679c\u5934\u8282\u70b9\u4e0d\u4e3a\u7a7a\uff0c\u8bf4\u660e\u5df2\u7ecf\u6709\u94fe\u8868\u5b58\u5728\uff0c\u6211\u4eec\u9700\u8981\u904d\u5386\u94fe\u8868\uff1a<\/p>\n\n\n\n
          \n
        • \u5982\u679c\u53d1\u73b0\u67d0\u4e2a\u8282\u70b9\u7684key\u4e0e\u5f53\u524dkey\u76f8\u7b49\uff0c\u5219\u66f4\u65b0\u5176value\uff0c\u5e76\u8fd4\u56de\u65e7value\uff1b<\/li>\n\n\n\n
        • \u5982\u679c\u904d\u5386\u5230\u94fe\u8868\u672b\u5c3e\u4ecd\u672a\u627e\u5230\uff0c\u5219\u5c06\u65b0\u8282\u70b9\u63d2\u5165\u94fe\u8868\u5c3e\u90e8\u3002<\/li>\n<\/ul>\n\n\n\n
          \u5177\u4f53\u5b9e\u73b0\u5982\u4e0b\uff1a<\/p>\n\n\n\n
          public V put(K key, V value) {\n    int keyIndex = indexOf(key);\n    Node<K, V> kvNode = table[keyIndex];\n    if (kvNode == null) {\n        table[keyIndex] = new Node<>(key, value);\n        return null;\n    }\n\n    while (true) {\n        if (kvNode.key.equals(key)) {\n            V oldValue = kvNode.value;\n            kvNode.value = value;\n            return oldValue;\n        }\n        if (kvNode.next == null) {\n            kvNode.next = new Node<>(key, value);\n            return null;\n        }\n        kvNode = kvNode.next;\n    }\n}<\/code><\/pre>\n\n\n\n
          \u8fd9\u6837\uff0cput<\/code>\u5c31\u5b8c\u6210\u4e86\u3002<\/p>\n\n\n\n
          \n\n\n\n
          \u63a5\u4e0b\u6765\u662fget<\/code>\u51fd\u6570\u3002<\/p>\n\n\n\n
          \u903b\u8f91\u7c7b\u4f3c\uff1a\u5148\u8ba1\u7b97\u89d2\u6807\uff0c\u83b7\u53d6\u94fe\u8868\u5934\uff0c\u7136\u540e\u904d\u5386\u94fe\u8868\uff1a<\/p>\n\n\n\n
          public V get(K key) {\n    int keyIndex = indexOf(key);\n    Node<K, V> head = table[keyIndex];\n    while (head != null) {\n        if (head.key.equals(key)) {\n            return head.value;\n        }\n        head = head.next;\n    }\n    return null;\n}<\/code><\/pre>\n\n\n\n
          \n\n\n\n
          remove<\/code>\u4e5f\u5dee\u4e0d\u591a\u3002<\/p>\n\n\n\n
          \u6211\u4eec\u4ecd\u7136\u5148\u8ba1\u7b97\u89d2\u6807\uff0c\u62ff\u5230\u94fe\u8868\u5934\u3002<\/p>\n\n\n\n
          \u5148\u5224\u65ad\u5934\u8282\u70b9\u662f\u5426\u4e3anull\uff0c\u5982\u679c\u662f\uff0c\u76f4\u63a5\u8fd4\u56denull\u3002<\/p>\n\n\n\n
          \u5982\u679c\u4e0d\u662f\uff0c\u5148\u5224\u65ad\u5934\u8282\u70b9\u662f\u4e0d\u662f\u8981\u5220\u9664\u7684key\uff1a<\/p>\n\n\n\n
          if (head.key.equals(key)) {\n    table[index] = head.next; \/\/ \u5934\u8282\u70b9\u79fb\u9664\uff0c\u6307\u5411\u4e0b\u4e00\u4e2a\n    return head.value;\n}<\/code><\/pre>\n\n\n\n
          \u5982\u679c\u4e0d\u662f\u5934\u8282\u70b9\uff0c\u5c31\u9700\u8981\u904d\u5386\u94fe\u8868\uff0c\u627e\u5230\u76ee\u6807\u8282\u70b9\u53ca\u5176\u524d\u9a71\uff1a<\/p>\n\n\n\n
          Node prev = head;\nNode curr = head.next;\nwhile (curr != null) {\n    if (curr.key.equals(key)) {\n        prev.next = curr.next; \/\/ \u8df3\u8fc7\u5f53\u524d\u8282\u70b9\n        return curr.value;\n    }\n    prev = curr;\n    curr = curr.next;\n}\nreturn null;<\/code><\/pre>\n\n\n\n
          public V remove(K key) {\n    int keyIndex = indexOf(key);\n    if (head == null) {\n        return null;\n    }\n    if (head.key.equals(key)) {\n        table[keyIndex] = head.next;\n        return head.value;\n    }\n    Node<K, V> pre = head;\n    Node<K, V> current = head.next;\n    while (current != null) {\n        if (current.key.equals(key)) {\n            pre.next = current.next;\n            return current.value;\n        }\n        pre = current;\n        current = current.next;\n    }\n    return null;\n}<\/code><\/pre>\n\n\n\n
          \n\n\n\n
          \u6700\u540e\u5b9e\u73b0size()<\/code>\u51fd\u6570\u3002<\/p>\n\n\n\n
          \u4f46\u73b0\u5728\u4e0d\u80fd\u518d\u7528table.length<\/code>\u4e86\uff0c\u56e0\u4e3a\u90a3\u662f\u6570\u7ec4\u957f\u5ea6\uff0c\u4e0d\u662f\u5b9e\u9645\u5143\u7d20\u4e2a\u6570\u3002
          \u6211\u4eec\u9700\u8981\u81ea\u5df1\u7ef4\u62a4\u4e00\u4e2asize<\/code>\u53d8\u91cf\uff1a<\/p>\n\n\n\n
          private int size = 0;<\/code><\/pre>\n\n\n\n
          \u5728put<\/code>\u6210\u529f\u63d2\u5165\u65b0\u8282\u70b9\u65f6\uff08\u5373\u672a\u8986\u76d6\u5df2\u6709key\uff09\uff0csize++<\/code>\uff1b
          \u5728remove<\/code>\u6210\u529f\u5220\u9664\u8282\u70b9\u65f6\uff0csize--<\/code>\u3002<\/p>\n\n\n\n
          \u6ce8\u610f\uff1a\u53ea\u6709\u771f\u6b63\u65b0\u589e\u8282\u70b9\u624d\u589e\u52a0size<\/code>\uff0c\u5982\u679c\u53ea\u662f\u66f4\u65b0\u5df2\u6709key\u7684value\uff0c\u5219\u4e0d\u589e\u52a0\u3002<\/p>\n\n\n\n
          \n\n\n\n
          \u73b0\u5728\u6211\u4eec\u56de\u5230\u6d4b\u8bd5\uff0c\u5c1d\u8bd5\u63d2\u516510\u4e07\u4e2a\u5143\u7d20\u3002<\/p>\n\n\n\n
          \u867d\u7136\u903b\u8f91\u6b63\u786e\uff0c\u4f46\u6027\u80fd\u4f9d\u7136\u5f88\u6162\u3002<\/p>\n\n\n\n
          \u6211\u4eec\u5206\u6790\u539f\u56e0\uff1a\u5f53\u524dtable<\/code>\u957f\u5ea6\u662f10\uff0c\u5373\u4f7f\u5e73\u5747\u5206\u914d\uff0c\u6bcf\u4e2a\u94fe\u8868\u4e5f\u6709\u7ea61\u4e07\u6761\u6570\u636e\u3002
          \u67e5\u627e\u3001\u63d2\u5165\u3001\u5220\u9664\u90fd\u8981\u904d\u5386\u957f\u7ea61\u4e07\u7684\u94fe\u8868\uff0c\u65f6\u95f4\u590d\u6742\u5ea6\u63a5\u8fd1O(n)\uff0c\u6027\u80fd\u6781\u5dee\u3002<\/p>\n\n\n\n
          \u89e3\u51b3\u65b9\u6848\uff1a\u52a8\u6001\u6269\u5bb9<\/strong>\u3002<\/p>\n\n\n\n
          \n\n\n\n
          \u6211\u4eec\u8bbe\u5b9a\u6269\u5bb9\u6761\u4ef6\uff1a\u5f53size >= table.length * 0.75<\/code>\u65f6\u89e6\u53d1\u6269\u5bb9\u3002
          \u8fd9\u4e2a0.75\u79f0\u4e3a\u8d1f\u8f7d\u56e0\u5b50\uff08load factor\uff09\u3002<\/p>\n\n\n\n
          \u6211\u4eec\u5199\u4e00\u4e2a\u51fd\u6570\uff1a<\/p>\n\n\n\n
          private void resizeIfNecessary() {\n    if (this.size < table.length * 0.75) {\n        return;\n    }\n    Node<K, V>[] newTable = new Node[this.table.length * 2];\n    for (Node<K, V> head : this.table) {\n        if (head == null) {\n            continue;\n        }\n        Node<K, V> current = head;\n        while (current != null) {\n            int newIndex = current.key.hashCode() % newTable.length;\n            if (newTable[newIndex] == null) {\n                newTable[newIndex] = current;\n                current.next = null;\n                current = current.next;\n            } else {\n                Node<K, V> next = current.next;\n                newTable[newIndex].next = current;\n                newTable[newIndex] = current;\n                current = next;\n            }\n        }\n    }\n}<\/code><\/pre>\n\n\n\n
          \u8fd9\u5c31\u662f\u7ecf\u5178\u7684\u5934\u63d2\u6cd5<\/strong>\uff08Head Insertion\uff09\uff1a
          \u5c06\u539f\u94fe\u8868\u4e2d\u7684\u8282\u70b9\u9010\u4e2a\u53d6\u51fa\uff0c\u63d2\u5165\u5230\u65b0\u6570\u7ec4\u5bf9\u5e94\u4f4d\u7f6e\u7684\u94fe\u8868\u5934\u90e8\u3002<\/p>\n\n\n\n
          \u6ce8\u610f\uff1a\u5934\u63d2\u6cd5\u4f1a\u5bfc\u81f4\u94fe\u8868\u987a\u5e8f\u53cd\u8f6c\u3002<\/p>\n\n\n\n
          \u6211\u4eec\u5728\u6bcf\u6b21put<\/code>\u6210\u529fsize++\u65b0\u589e\u8282\u70b9\u540e\u8c03\u7528resizeIfNecessary()<\/code>\u3002<\/p>\n\n\n\n
          \n\n\n\n
          \u518d\u6b21\u8fd0\u884c10\u4e07\u6761\u6570\u636e\u7684\u6d4b\u8bd5\u2014\u2014\u8fd9\u6b21\u4ec5\u8017\u65f6\u7ea630ms\uff0c\u8fdc\u5feb\u4e8e\u4e4b\u524d\u3002<\/p>\n\n\n\n
          \u8bf4\u660e\u901a\u8fc7\u6269\u5bb9\u6253\u6563\u94fe\u8868\uff0c\u663e\u8457\u63d0\u5347\u4e86\u6027\u80fd\u3002<\/p>\n\n\n\n
          \n\n\n\n
          \u8fdb\u4e00\u6b65\u4f18\u5316\uff1a\u4f7f\u7528\u4f4d\u8fd0\u7b97\u66ff\u4ee3\u53d6\u6a21\u3002<\/p>\n\n\n\n
          \u6211\u4eec\u77e5\u9053\uff0c\u5728\u4e8c\u8fdb\u5236\u4e2d\uff0c\u53ea\u67091 & 1 = 1\uff0c\u5176\u4f59\u90fd\u4e3a0\u3002<\/p>\n\n\n\n
          \u5982\u679c\u6211\u4eec\u80fd\u8ba9table.length<\/code>\u662f2\u7684\u5e42\u6b21\uff08\u598216\u300132\u300164\uff09\uff0c\u90a3\u4e48table.length - 1<\/code>\u7684\u4e8c\u8fdb\u5236\u4f4e\u4f4d\u5168\u4e3a1\u3002<\/p>\n\n\n\n
          \u4f8b\u5982\uff1a<\/p>\n\n\n\n
            \n
          • 16 \u2192 \u4e8c\u8fdb\u5236 10000<\/code><\/li>\n\n\n\n
          • 15 \u2192 \u4e8c\u8fdb\u5236 01111<\/code><\/li>\n<\/ul>\n\n\n\n
            \u6b64\u65f6\uff0chashCode & (table.length - 1)<\/code> \u7b49\u4ef7\u4e8e hashCode % table.length<\/code>\uff0c\u4f46\u901f\u5ea6\u66f4\u5feb\u3002<\/p>\n\n\n\n
            \u6240\u4ee5\u6211\u4eec\u4fee\u6539\u521d\u59cb\u5316\uff1a<\/p>\n\n\n\n
            table = new Node[16]; \/\/ \u6539\u4e3a2\u7684\u5e42<\/code><\/pre>\n\n\n\n
            \u5e76\u4fee\u6539indexOf<\/code>\u65b9\u6cd5\uff1a<\/p>\n\n\n\n
            private int indexOf(Object key) {\n    return key.hashCode() & (newtable.length - 1);\n}<\/code><\/pre>\n\n\n\n
            \u6ce8\u610f\uff1a\u8fd9\u91cc\u4e0d\u518d\u9700\u8981Math.abs()<\/code>\uff0c\u56e0\u4e3a\u8d1f\u6570\u7684\u8865\u7801\u4e0e\u8fd0\u7b97\u4e5f\u80fd\u5f97\u5230\u5408\u6cd5\u7d22\u5f15\u3002<\/p>\n\n\n\n
            \u540c\u65f6\u5728\u6269\u5bb9\u65f6\u4e5f\u8981\u4fdd\u6301\u65b0\u957f\u5ea6\u4e3a2\u7684\u5e42\uff08oldLength * 2<\/code>\u81ea\u7136\u6ee1\u8db3\uff09\u3002<\/p>\n\n\n\n
            \u4fee\u6539\u5b8c\u6210\u540e\u8fd0\u884c\u6d4b\u8bd5\u2014\u2014\u4f9d\u7136\u901a\u8fc7\uff0c\u8bf4\u660e\u903b\u8f91\u6b63\u786e\u3002<\/p>\n\n\n\n
            \n\n\n\n
            \u6211\u4eec\u8fd8\u53ef\u4ee5\u52a0\u65e5\u5fd7\u89c2\u5bdf\u6269\u5bb9\u8fc7\u7a0b\uff1a<\/p>\n\n\n\n
            System.out.println(\"\u5f53\u524d\u6269\u5bb9\u4e86\uff0c\u6269\u5bb9\u5230\uff1a\" + newTable.length);<\/code><\/pre>\n\n\n\n
            \u8fd0\u884c\u540e\u53ef\u4ee5\u770b\u5230\uff1atable\u4ece16\u4e0d\u65ad\u7ffb\u500d\uff0c\u6700\u7ec8\u8fbe\u5230262144\uff08\u7ea626\u4e07\uff09\uff0c\u8bf4\u660e\u7ecf\u5386\u4e86\u591a\u6b21\u6269\u5bb9\u3002<\/p>\n\n\n\n
            \n\n\n\n
            \u4f46\u8fd8\u6709\u4e00\u4e2a\u95ee\u9898\uff1a\u5373\u4f7f\u6269\u5bb9\u4e86\uff0c\u4e5f\u4e0d\u80fd\u4fdd\u8bc1\u6bcf\u4e2a\u94fe\u8868\u90fd\u5f88\u77ed\u3002<\/p>\n\n\n\n
            \u5982\u679c\u54c8\u5e0c\u5206\u5e03\u6781\u4e0d\u5747\u5300\uff08\u4f8b\u5982\u5927\u91cfkey\u7684hashCode<\/code>\u96c6\u4e2d\u5728\u67d0\u51e0\u4e2a\u503c\uff09\uff0c\u5c31\u4f1a\u5bfc\u81f4\u67d0\u4e9b\u94fe\u8868\u7279\u522b\u957f\uff0c\u5176\u4ed6\u4e3a\u7a7a\u3002<\/p>\n\n\n\n
            \u8fd9\u65f6\u641c\u7d22\u6027\u80fd\u53c8\u9000\u5316\u4e3aO(n)\u3002<\/p>\n\n\n\n
            \u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0cJDK 8\u5f15\u5165\u4e86\u7ea2\u9ed1\u6811\u4f18\u5316<\/strong>\uff1a
            \u5f53\u67d0\u4e2a\u94fe\u8868\u957f\u5ea6\u8d85\u8fc7\u9608\u503c\uff08\u9ed8\u8ba48\uff09\u4e14\u6570\u7ec4\u957f\u5ea6\u5927\u4e8e64\u65f6\uff0c\u94fe\u8868\u8f6c\u4e3a\u7ea2\u9ed1\u6811\uff0c\u4f7f\u67e5\u627e\u53d8\u4e3aO(log n)\u3002<\/p>\n\n\n\n
            \u4e0d\u8fc7\u5728\u8fd9\u91cc\u6211\u4e0d\u6253\u7b97\u5e26\u7740\u5927\u5bb6\u624b\u5199\u7ea2\u9ed1\u6811\uff0c\u56e0\u4e3a\u5b9e\u73b0\u590d\u6742\u4e14\u504f\u79bb\u4e3b\u9898\u3002<\/p>\n\n\n\n
            \u4f46\u4f60\u8981\u660e\u767d\uff1a\u4ec5\u9760\u6269\u5bb9\u65e0\u6cd5\u89e3\u51b3\u6781\u7aef\u54c8\u5e0c\u51b2\u7a81\u5e26\u6765\u7684\u6027\u80fd\u95ee\u9898<\/strong>\u3002<\/p>\n\n\n\n
            \n\n\n\n
            \u6700\u540e\u6211\u4eec\u8ba8\u8bba\u4e00\u4e2a\u7ecf\u5178\u95ee\u9898\uff1a\u4e3a\u4ec0\u4e48HashMap\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\u53ef\u80fd\u9020\u6210\u6b7b\u5faa\u73af\uff1f<\/strong><\/p>\n\n\n\n
            \u5173\u952e\u5c31\u5728\u4e8e\u6211\u4eec\u4f7f\u7528\u7684\u5934\u63d2\u6cd5<\/strong>\u3002<\/p>\n\n\n\n
            \u5047\u8bbe\u6709\u4e24\u4e2a\u7ebf\u7a0b\u540c\u65f6\u89e6\u53d1\u6269\u5bb9\uff1a<\/p>\n\n\n\n
            \u7ebf\u7a0bA\u6b63\u5728\u8fc1\u79fb\u67d0\u4e2a\u94fe\u8868\uff08\u6bd4\u5982table[i]<\/code>\u4e0a\u7684\u94fe\u8868\uff09\uff0c\u5b83\u53d6\u51fa\u7b2c\u4e00\u4e2a\u8282\u70b9node1<\/code>\uff0c\u8ba1\u7b97\u5176\u5728\u65b0\u8868\u4e2d\u7684\u4f4d\u7f6e\uff0c\u51c6\u5907\u5c06\u5176\u63d2\u5165\u65b0\u8868\u5934\u3002<\/p>\n\n\n\n
            \u4f46\u5728\u63d2\u5165\u524d\uff0cCPU\u5207\u6362\u5230\u7ebf\u7a0bB\uff0c\u7ebf\u7a0bB\u5b8c\u6210\u4e86\u6574\u4e2a\u94fe\u8868\u7684\u8fc1\u79fb\uff0c\u4f7f\u7528\u5934\u63d2\u6cd5\u6539\u53d8\u4e86\u94fe\u8868\u987a\u5e8f\u3002<\/p>\n\n\n\n
            \u5f53\u7ebf\u7a0bA\u6062\u590d\u6267\u884c\u65f6\uff0c\u5b83\u7ee7\u7eed\u8fc1\u79fb\u5269\u4e0b\u7684\u8282\u70b9\uff0c\u4f46\u7531\u4e8e\u5934\u63d2\u6cd5\u7684\u6307\u9488\u64cd\u4f5c\uff0c\u53ef\u80fd\u5bfc\u81f4\u94fe\u8868\u5f62\u6210\u73af\u5f62\u7ed3\u6784\u2014\u2014\u67d0\u4e2a\u8282\u70b9\u7684next<\/code>\u6307\u5411\u4e86\u81ea\u5df1\u6216\u524d\u9762\u7684\u8282\u70b9\u3002<\/p>\n\n\n\n
            \u4e00\u65e6\u5f62\u6210\u73af\uff0c\u4efb\u4f55\u5bf9\u8be5\u94fe\u8868\u7684\u64cd\u4f5c\uff08\u5982get<\/code>\u3001put<\/code>\uff09\u90fd\u4f1a\u9677\u5165\u65e0\u9650\u5faa\u73af\u3002<\/p>\n\n\n\n
            \u8fd9\u5c31\u662fJDK 7 HashMap\u5728\u5e76\u53d1\u73af\u5883\u4e0b\u53ef\u80fd\u51fa\u73b0\u6b7b\u5faa\u73af\u7684\u539f\u56e0\u3002<\/p>\n\n\n\n
            \n\n\n\n
            \u4e3a\u6b64\uff0cJDK 8\u5c06\u5934\u63d2\u6cd5\u6539\u4e3a\u5c3e\u63d2\u6cd5<\/strong>\uff1a<\/p>\n\n\n\n
            \u8fc1\u79fb\u65f6\u603b\u662f\u628a\u8282\u70b9\u63d2\u5165\u94fe\u8868\u5c3e\u90e8\uff0c\u4fdd\u8bc1\u987a\u5e8f\u4e0d\u53d8\uff0c\u907f\u514d\u6210\u73af\u3002<\/p>\n\n\n\n
            \u4f46\u5c3e\u63d2\u6cd5\u4e5f\u6709\u4ee3\u4ef7\uff1a\u5fc5\u987b\u904d\u5386\u5230\u94fe\u8868\u672b\u5c3e\u624d\u80fd\u63d2\u5165\uff0c\u6027\u80fd\u7565\u4f4e\u3002<\/p>\n\n\n\n
            \n\n\n\n
            \u6211\u4e2a\u4eba\u7684\u770b\u6cd5\u662f\uff1a<\/p>\n\n\n\n
              \n
            1. \u5934\u63d2\u6cd5\u5b9e\u73b0\u7b80\u5355\u3001\u6027\u80fd\u9ad8<\/strong>\uff1a\u53ea\u9700\u4fee\u6539\u5934\u6307\u9488\uff0c\u65e0\u9700\u904d\u5386\u3002<\/li>\n\n\n\n
            2. \u987a\u5e8f\u53d8\u5316\u65e0\u5173\u7d27\u8981<\/strong>\uff1aHashMap\u672c\u5c31\u4e0d\u4fdd\u8bc1\u904d\u5386\u987a\u5e8f\u3002<\/li>\n\n\n\n
            3. HashMap\u672c\u8eab\u5c31\u662f\u7ebf\u7a0b\u4e0d\u5b89\u5168\u7684\u7c7b<\/strong>\uff1a\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4f7f\u7528\u672c\u8eab\u5c31\u662f\u9519\u8bef\u505a\u6cd5\uff0c\u51fa\u73b0\u95ee\u9898\u662f\u4f7f\u7528\u8005\u7684\u8d23\u4efb\u3002<\/li>\n<\/ol>\n\n\n\n
              \u6b63\u56e0\u4e3a\u5c11\u6570\u4eba\u9519\u8bef\u4f7f\u7528\uff0cJDK\u88ab\u8feb\u727a\u7272\u6240\u6709\u7528\u6237\u7684\u6027\u80fd\uff08\u6539\u4e3a\u5c3e\u63d2\u6cd5\uff09\uff0c\u8ba9\u6240\u6709\u4eba\u627f\u62c5\u6269\u5bb9\u6210\u672c\u3002
              \u8fd9\u5728\u6211\u770b\u6765\u662f\u4e00\u4ef6\u975e\u5e38\u8bbd\u523a\u7684\u4e8b\u3002<\/p>\n\n\n\n
              \n\n\n\n
              \u8fd9\u662f\u4eca\u5929\u7684\u601d\u8003\u9898\uff1a
              \u4f60\u53ef\u4ee5\u7ed9HashMap\u589e\u52a0\u4e00\u4e2a\u904d\u5386\u7684\u51fd\u6570\u5417\uff1f<\/p>\n","protected":false},"excerpt":{"rendered":"
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