{"id":393,"date":"2025-09-15T18:11:13","date_gmt":"2025-09-15T10:11:13","guid":{"rendered":"https:\/\/heyingnian.com\/?p=393"},"modified":"2025-09-15T18:11:38","modified_gmt":"2025-09-15T10:11:38","slug":"leetcode-138","status":"publish","type":"post","link":"https:\/\/heyingnian.com\/index.php\/2025\/09\/15\/leetcode-138\/","title":{"rendered":"\u590d\u5236\u5e26\u968f\u673a\u6307\u9488\u7684\u94fe\u8868"},"content":{"rendered":"\n<h1 class=\"wp-block-heading\">\ud83d\udd17 \u590d\u5236\u5e26\u968f\u673a\u6307\u9488\u7684\u94fe\u8868<\/h1>\n\n\n\n<p>\u9898\u76ee\u6765\u6e90\uff1a<a target=\"_blank\" rel=\"noreferrer noopener\"><a href=\"https:\/\/leetcode.cn\/problems\/copy-list-with-random-pointer\/?envType=study-plan-v2&amp;envId=top-100-liked\" target=\"_blank\" rel=\"noopener\">138. \u968f\u673a\u94fe\u8868\u7684\u590d\u5236 &#8211; \u529b\u6263\uff08LeetCode\uff09<\/a><\/a><\/p>\n\n\n\n<p>\ud83d\udccc \u9898\u76ee\u63cf\u8ff0<\/p>\n\n\n\n<p>\u7ed9\u4f60\u4e00\u4e2a\u957f\u5ea6\u4e3a <code>n<\/code> \u7684\u94fe\u8868\uff0c\u6bcf\u4e2a\u8282\u70b9\u5305\u542b\u4e00\u4e2a\u989d\u5916\u589e\u52a0\u7684\u968f\u673a\u6307\u9488 <code>random<\/code>\uff0c\u8be5\u6307\u9488\u53ef\u4ee5\u6307\u5411\u94fe\u8868\u4e2d\u7684<strong>\u4efb\u4f55\u8282\u70b9\u6216\u7a7a\u8282\u70b9<\/strong>\u3002<\/p>\n\n\n\n<p>\u8981\u6c42\u4f60\u6784\u9020\u8fd9\u4e2a\u94fe\u8868\u7684<strong>\u6df1\u62f7\u8d1d<\/strong>\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6df1\u62f7\u8d1d\u5e94\u7531\u00a0<code>n<\/code>\u00a0\u4e2a<strong>\u5168\u65b0\u8282\u70b9<\/strong>\u7ec4\u6210\uff0c\u6bcf\u4e2a\u65b0\u8282\u70b9\u7684\u503c\u7b49\u4e8e\u539f\u8282\u70b9\u3002<\/li>\n\n\n\n<li>\u65b0\u8282\u70b9\u7684\u00a0<code>next<\/code>\u00a0\u548c\u00a0<code>random<\/code>\u00a0\u6307\u9488\u5fc5\u987b\u6307\u5411<strong>\u590d\u5236\u94fe\u8868\u4e2d\u7684\u65b0\u8282\u70b9<\/strong>\u3002<\/li>\n\n\n\n<li><strong>\u4e0d\u80fd\u6307\u5411\u539f\u94fe\u8868\u4e2d\u7684\u4efb\u4f55\u8282\u70b9<\/strong>\u3002<\/li>\n\n\n\n<li>\u8f93\u5165\/\u8f93\u51fa\u4ee5\u00a0<code>[val, random_index]<\/code>\u00a0\u5f62\u5f0f\u8868\u793a\uff0c<code>random_index<\/code>\u00a0\u662f\u76ee\u6807\u8282\u70b9\u7684\u7d22\u5f15\uff080 \u5230 n-1\uff09\uff0c\u82e5\u4e3a\u00a0<code>null<\/code>\u00a0\u8868\u793a\u4e0d\u6307\u5411\u4efb\u4f55\u8282\u70b9\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u2705 \u793a\u4f8b\u89e3\u6790<\/p>\n\n\n\n<p>\u793a\u4f8b 1\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/heyingnian.com\/wp-content\/uploads\/2025\/09\/image-27-1024x208.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"208\" data-original=\"https:\/\/heyingnian.com\/wp-content\/uploads\/2025\/09\/image-27-1024x208.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" class=\"wp-image-394\"  sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/div><\/figure>\n\n\n\n<p>\u8f93\u5165\uff1a<code>head = [[7,null],[13,0],[11,4],[10,2],[1,0]]<\/code><br>\u8f93\u51fa\uff1a<code>[[7,null],[13,0],[11,4],[10,2],[1,0]]<\/code><br>\u89e3\u91ca\uff1a\u6bcf\u4e2a\u8282\u70b9\u503c\u590d\u5236\uff0crandom \u6307\u9488\u6307\u5411\u590d\u5236\u540e\u94fe\u8868\u4e2d\u5bf9\u5e94\u7684\u65b0\u8282\u70b9\u3002<\/p>\n\n\n\n<p>\u793a\u4f8b 2\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/heyingnian.com\/wp-content\/uploads\/2025\/09\/image-28-1024x167.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"167\" data-original=\"https:\/\/heyingnian.com\/wp-content\/uploads\/2025\/09\/image-28-1024x167.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" class=\"wp-image-395\"  sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/div><\/figure>\n\n\n\n<p>\u8f93\u5165\uff1a<code>head = [[1,1],[2,1]]<\/code><br>\u8f93\u51fa\uff1a<code>[[1,1],[2,1]]<\/code><br>\u89e3\u91ca\uff1a\u8282\u70b91\u7684random\u6307\u5411\u8282\u70b92\uff0c\u8282\u70b92\u7684random\u4e5f\u6307\u5411\u8282\u70b92\uff08\u81ea\u8eab\uff09\u3002<\/p>\n\n\n\n<p>\u793a\u4f8b 3\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/heyingnian.com\/wp-content\/uploads\/2025\/09\/image-29-1024x179.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"179\" data-original=\"https:\/\/heyingnian.com\/wp-content\/uploads\/2025\/09\/image-29-1024x179.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" class=\"wp-image-396\"  sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/div><\/figure>\n\n\n\n<p>\u8f93\u5165\uff1a<code>head = [[3,null],[3,0],[3,null]]<\/code><br>\u8f93\u51fa\uff1a<code>[[3,null],[3,0],[3,null]]<\/code><\/p>\n\n\n\n<p>\u26a0\ufe0f \u63d0\u793a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>0 &lt;= n &lt;= 1000<\/code><\/li>\n\n\n\n<li><code>-10\u2074 &lt;= Node.val &lt;= 10\u2074<\/code><\/li>\n\n\n\n<li><code>Node.random<\/code>\u00a0\u4e3a\u00a0<code>null<\/code>\u00a0\u6216\u6307\u5411\u94fe\u8868\u4e2d\u7684\u8282\u70b9<\/li>\n<\/ul>\n\n\n\n<p>\ud83d\udca1 \u89e3\u6cd5\uff1a\u54c8\u5e0c\u8868\u6620\u5c04\u6cd5 \u2014\u2014 O(n) \u65f6\u95f4\uff0cO(n) \u7a7a\u95f4<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Solution {\n    public Node copyRandomList(Node head) {\n        if (head == null) {\n            return null;\n        }\n\n        \/\/ \u7b2c\u4e00\u6b65\uff1a\u904d\u5386\u539f\u94fe\u8868\uff0c\u521b\u5efa\u65b0\u8282\u70b9\u5e76\u5efa\u7acb\u6620\u5c04\n        HashMap&lt;Node, Node> map = new HashMap&lt;>();\n        Node p = head;\n\n        while (p != null) {\n            map.put(p, new Node(p.val));\n            p = p.next;\n        }\n\n        \/\/ \u7b2c\u4e8c\u6b65\uff1a\u518d\u6b21\u904d\u5386\uff0c\u8bbe\u7f6e\u65b0\u8282\u70b9\u7684 next \u548c random\n        p = head;\n        while (p != null) {\n            Node temp = map.get(p);\n            temp.next = map.get(p.next);   \/\/ \u65b0\u8282\u70b9\u7684 next \u6307\u5411\u5bf9\u5e94\u65b0\u8282\u70b9\n            temp.random = map.get(p.random); \/\/ \u65b0\u8282\u70b9\u7684 random \u6307\u5411\u5bf9\u5e94\u65b0\u8282\u70b9\n            p = p.next;\n        }\n\n        \/\/ \u7b2c\u4e09\u6b65\uff1a\u8fd4\u56de\u65b0\u94fe\u8868\u5934\u8282\u70b9\n        return map.get(head);\n    }\n}<\/code><\/pre>\n\n\n\n<p>\ud83d\udcca \u590d\u6742\u5ea6\u5206\u6790<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u65f6\u95f4\u590d\u6742\u5ea6\uff1aO(n)<\/strong>\n<ul class=\"wp-block-list\">\n<li>\u4e24\u6b21\u904d\u5386\u94fe\u8868\uff0c\u6bcf\u6b21 O(n)\uff0c\u54c8\u5e0c\u8868\u64cd\u4f5c\u5e73\u5747 O(1)\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u7a7a\u95f4\u590d\u6742\u5ea6\uff1aO(n) \u2705<\/strong>\n<ul class=\"wp-block-list\">\n<li>\u4f7f\u7528\u54c8\u5e0c\u8868\u5b58\u50a8\u00a0<code>n<\/code>\u00a0\u4e2a\u8282\u70b9\u6620\u5c04\u5173\u7cfb\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p>\ud83e\udde9 \u89e3\u9898\u601d\u8def<\/p>\n\n\n\n<p>\u6838\u5fc3\u601d\u60f3\uff1a<strong>\u4e24\u6b21\u904d\u5386 + \u54c8\u5e0c\u8868\u5efa\u7acb\u539f\u8282\u70b9\u4e0e\u65b0\u8282\u70b9\u7684\u4e00\u4e00\u6620\u5c04<\/strong><\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u8fb9\u754c\u5904\u7406\uff1a\n<ul class=\"wp-block-list\">\n<li>\u82e5\u00a0<code>head == null<\/code>\uff0c\u76f4\u63a5\u8fd4\u56de\u00a0<code>null<\/code>\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>\u7b2c\u4e00\u6b21\u904d\u5386 \u2014\u2014 \u521b\u5efa\u8282\u70b9\u5e76\u5efa\u7acb\u6620\u5c04\uff1a\n<ul class=\"wp-block-list\">\n<li>\u904d\u5386\u539f\u94fe\u8868\u6bcf\u4e2a\u8282\u70b9\u00a0<code>p<\/code>\u3002<\/li>\n\n\n\n<li>\u4e3a\u6bcf\u4e2a\u00a0<code>p<\/code>\u00a0\u521b\u5efa\u4e00\u4e2a\u65b0\u8282\u70b9\u00a0<code>new Node(p.val)<\/code>\u3002<\/li>\n\n\n\n<li>\u5b58\u5165\u54c8\u5e0c\u8868\u00a0<code>map.put(p, newNode)<\/code>\u00a0\u2192 \u5efa\u7acb\u201c\u65e7\u8282\u70b9 \u2192 \u65b0\u8282\u70b9\u201d\u7684\u6620\u5c04\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>\u7b2c\u4e8c\u6b21\u904d\u5386 \u2014\u2014 \u8bbe\u7f6e\u6307\u9488\u5173\u7cfb\uff1a\n<ul class=\"wp-block-list\">\n<li>\u518d\u6b21\u4ece\u5934\u904d\u5386\u539f\u94fe\u8868\u3002<\/li>\n\n\n\n<li>\u5bf9\u6bcf\u4e2a\u539f\u8282\u70b9\u00a0<code>p<\/code>\uff1a\n<ul class=\"wp-block-list\">\n<li>\u83b7\u53d6\u5bf9\u5e94\u65b0\u8282\u70b9\u00a0<code>temp = map.get(p)<\/code><\/li>\n\n\n\n<li>\u8bbe\u7f6e\u00a0<code>temp.next = map.get(p.next)<\/code>\u00a0\u2192 \u82e5\u00a0<code>p.next<\/code>\u00a0\u4e3a null\uff0c\u5219\u8fd4\u56de null<\/li>\n\n\n\n<li>\u8bbe\u7f6e\u00a0<code>temp.random = map.get(p.random)<\/code>\u00a0\u2192 \u540c\u7406\uff0c\u652f\u6301 null<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>\u5b8c\u6210\u6240\u6709\u65b0\u8282\u70b9\u7684\u8fde\u63a5\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>\u8fd4\u56de\u7ed3\u679c\uff1a\n<ul class=\"wp-block-list\">\n<li><code>map.get(head)<\/code>\u00a0\u5373\u4e3a\u590d\u5236\u94fe\u8868\u7684\u5934\u8282\u70b9\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>\ud83d\udd17 \u590d\u5236\u5e26\u968f\u673a\u6307\u9488\u7684\u94fe\u8868 \u9898\u76ee\u6765\u6e90\uff1a138. \u968f\u673a\u94fe\u8868\u7684\u590d\u5236 &#8211; \u529b\u6263\uff08LeetCode\uff09 \ud83d\udccc \u9898 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12,38],"tags":[15,14,51],"class_list":["post-393","post","type-post","status-publish","format-standard","hentry","category-algorithm","category-linked_list","tag-hash","tag-algorithm","tag-linked_list"],"_links":{"self":[{"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/393","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/comments?post=393"}],"version-history":[{"count":1,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/393\/revisions"}],"predecessor-version":[{"id":397,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/393\/revisions\/397"}],"wp:attachment":[{"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/media?parent=393"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/categories?post=393"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/tags?post=393"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}