{"id":1062,"date":"2025-12-26T05:12:34","date_gmt":"2025-12-25T21:12:34","guid":{"rendered":"https:\/\/www.guanhaobo.cn\/?p=1062"},"modified":"2025-12-26T05:13:18","modified_gmt":"2025-12-25T21:13:18","slug":"leetcode-287-%e5%af%bb%e6%89%be%e9%87%8d%e5%a4%8d%e6%95%b0","status":"publish","type":"post","link":"https:\/\/www.guanhaobo.cn\/?p=1062","title":{"rendered":"LeetCode 287 \u2013 \u5bfb\u627e\u91cd\u590d\u6570"},"content":{"rendered":"

\u9898\u76ee\u63cf\u8ff0<\/h1>\n

\u7ed9\u5b9a\u4e00\u4e2a\u5305\u542b n + 1 \u4e2a\u6574\u6570\u7684\u6570\u7ec4 nums \uff0c\u5176\u6570\u5b57\u90fd\u5728 [1, n] \u8303\u56f4\u5185\uff08\u5305\u62ec 1 \u548c n\uff09\uff0c\u53ef\u77e5\u81f3\u5c11\u5b58\u5728\u4e00\u4e2a\u91cd\u590d\u7684\u6574\u6570\u3002
\n\u5047\u8bbe nums \u53ea\u6709 \u4e00\u4e2a\u91cd\u590d\u7684\u6574\u6570 \uff0c\u8fd4\u56de \u8fd9\u4e2a\u91cd\u590d\u7684\u6570 \u3002
\n\u4f60\u8bbe\u8ba1\u7684\u89e3\u51b3\u65b9\u6848\u5fc5\u987b \u4e0d\u4fee\u6539 \u6570\u7ec4 nums \u4e14\u53ea\u7528\u5e38\u91cf\u7ea7 O(1) \u7684\u989d\u5916\u7a7a\u95f4\u3002<\/p>\n

\u8fdb\u9636\uff1a
\n\u5982\u4f55\u8bc1\u660e nums \u4e2d\u81f3\u5c11\u5b58\u5728\u4e00\u4e2a\u91cd\u590d\u7684\u6570\u5b57?
\n\u4f60\u53ef\u4ee5\u8bbe\u8ba1\u4e00\u4e2a\u7ebf\u6027\u7ea7\u65f6\u95f4\u590d\u6742\u5ea6 O(n) \u7684\u89e3\u51b3\u65b9\u6848\u5417\uff1f<\/p>\n

\u793a\u4f8b\uff1a
\n\u8f93\u5165\uff1anums = [1,3,4,2,2]
\n\u8f93\u51fa\uff1a2<\/p>\n

\u9898\u76ee\u5206\u6790<\/h1>\n

n + 1 \u4e2a\u6570\u5b57\uff0c\u5728 [1, n] \u8303\u56f4\u5185\uff0c\u610f\u5473\u7740\u53ef\u4ee5\u901a\u8fc7 \u4e0b\u6807 -> \u503c\uff0c\u6784\u6210\u94fe\u8868\u3002
\n\u94fe\u8868\u4e2d\u81f3\u5c11\u5b58\u5728\u4e00\u4e2a\u73af\uff0c\u800c\u91cd\u590d\u7684\u6570\u5b57\u5c31\u662f\u73af\u7684\u5165\u53e3\uff0c\u95ee\u9898\u8f6c\u6362\u6210\u5bfb\u627e\u94fe\u8868\u4e2d\u73af\u7684\u8d77\u70b9\u3002
\n\u6570\u5b57\u8303\u56f4\u662f [1, n]\uff0c\u8bf4\u660e 0 \u4e00\u5b9a\u4e0d\u5728\u73af\u5185\uff0c\u4ece 0 \u5f00\u59cb\u5feb\u6162\u6307\u9488\u5373\u53ef\u3002<\/p>\n

\u65f6\u95f4\u590d\u6742\u5ea6 O(n)\uff0c\u7a7a\u95f4\u590d\u6742\u5ea6 O(1)<\/p>\n

Java<\/h1>\n
public int findDuplicate(int[] nums) {\n    int slow = 0, fast = 0;\n    do {\n        slow = nums[slow];\n        fast = nums[nums[fast]];\n    } while (slow != fast);\n\n    fast = 0;\n    while (slow != fast) {\n        slow = nums[slow];\n        fast = nums[fast];\n    }\n    return slow;\n}\n<\/code><\/pre>\n
Kotlin<\/h1>\n
fun findDuplicate(nums: IntArray): Int {\n    var slow = 0\n    var fast = 0\n    \/\/ \u5feb\u6162\u6307\u9488\u5728\u73af\u4e2d\u76f8\u4ea4\n    do {\n        slow = nums[slow]\n        fast = nums[nums[fast]]\n    } while (slow != fast)\n\n    \/\/ \u5bfb\u627e\u73af\u7684\u8d77\u70b9\n    fast = 0\n    while (slow != fast) {\n        slow = nums[slow]\n        fast = nums[fast]\n    }\n    return slow\n}\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
\u9898\u76ee\u63cf\u8ff0 \u7ed9\u5b9a\u4e00\u4e2a\u5305\u542b n + 1 \u4e2a\u6574\u6570\u7684\u6570\u7ec4 nums \uff0c\u5176\u6570\u5b57\u90fd\u5728 [1, n] \u8303\u56f4\u5185\uff08\u5305\u62ec 1 \u548c  […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[20,92,73,84],"class_list":["post-1062","post","type-post","status-publish","format-standard","hentry","category-algo","tag-leetcode","tag-92","tag-73","tag-84"],"_links":{"self":[{"href":"https:\/\/www.guanhaobo.cn\/index.php?rest_route=\/wp\/v2\/posts\/1062","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.guanhaobo.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.guanhaobo.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.guanhaobo.cn\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.guanhaobo.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1062"}],"version-history":[{"count":2,"href":"https:\/\/www.guanhaobo.cn\/index.php?rest_route=\/wp\/v2\/posts\/1062\/revisions"}],"predecessor-version":[{"id":1064,"href":"https:\/\/www.guanhaobo.cn\/index.php?rest_route=\/wp\/v2\/posts\/1062\/revisions\/1064"}],"wp:attachment":[{"href":"https:\/\/www.guanhaobo.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1062"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.guanhaobo.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1062"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.guanhaobo.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1062"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}