{"id":143,"date":"2025-08-25T10:02:12","date_gmt":"2025-08-25T02:02:12","guid":{"rendered":"https:\/\/heyingnian.com\/?p=143"},"modified":"2025-08-26T15:46:07","modified_gmt":"2025-08-26T07:46:07","slug":"leetcode-3","status":"publish","type":"post","link":"https:\/\/heyingnian.com\/index.php\/2025\/08\/25\/leetcode-3\/","title":{"rendered":"\u65e0\u91cd\u590d\u5b57\u7b26\u7684\u6700\u957f\u5b50\u4e32"},"content":{"rendered":"\n<h1 class=\"wp-block-heading\">\ud83d\udd17 \u65e0\u91cd\u590d\u5b57\u7b26\u7684\u6700\u957f\u5b50\u4e32<\/h1>\n\n\n\n<p>\u9898\u76ee\u6765\u6e90\uff1a<a target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/leetcode.cn\/problems\/longest-substring-without-repeating-characters\/description\/?envType=study-plan-v2&amp;envId=top-100-liked\" target=\"_blank\" rel=\"noopener\">3. \u65e0\u91cd\u590d\u5b57\u7b26\u7684\u6700\u957f\u5b50\u4e32 &#8211; \u529b\u6263\uff08LeetCode\uff09<\/a><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\ud83d\udccc \u9898\u76ee\u63cf\u8ff0<\/p>\n\n\n\n<p>\u7ed9\u5b9a\u4e00\u4e2a\u5b57\u7b26\u4e32 <code>s<\/code>\uff0c\u8bf7\u4f60\u627e\u51fa\u5176\u4e2d<strong>\u4e0d\u542b\u6709\u91cd\u590d\u5b57\u7b26<\/strong>\u7684<strong>\u6700\u957f\u5b50\u4e32<\/strong>\u7684\u957f\u5ea6\u3002<\/p>\n\n\n\n<p><strong>\u6ce8\u610f<\/strong>\uff1a\u5b50\u4e32\uff08substring\uff09\u662f\u539f\u5b57\u7b26\u4e32\u4e2d\u8fde\u7eed\u7684\u4e00\u6bb5\u5b57\u7b26\u5e8f\u5217\uff0c\u4e0d\u540c\u4e8e\u5b50\u5e8f\u5217\uff08subsequence\uff09\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\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<ul class=\"wp-block-list\">\n<li>\u8f93\u5165\uff1a<code>s = \"abcabcbb\"<\/code><\/li>\n\n\n\n<li>\u8f93\u51fa\uff1a<code>3<\/code><\/li>\n\n\n\n<li>\u89e3\u91ca\uff1a\u65e0\u91cd\u590d\u5b57\u7b26\u7684\u6700\u957f\u5b50\u4e32\u662f&nbsp;<code>\"abc\"<\/code>\uff0c\u957f\u5ea6\u4e3a&nbsp;<code>3<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u793a\u4f8b 2\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8f93\u5165\uff1a<code>s = \"bbbbb\"<\/code><\/li>\n\n\n\n<li>\u8f93\u51fa\uff1a<code>1<\/code><\/li>\n\n\n\n<li>\u89e3\u91ca\uff1a\u6700\u957f\u5b50\u4e32\u662f&nbsp;<code>\"b\"<\/code>\uff0c\u957f\u5ea6\u4e3a&nbsp;<code>1<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u793a\u4f8b 3\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8f93\u5165\uff1a<code>s = \"pwwkew\"<\/code><\/li>\n\n\n\n<li>\u8f93\u51fa\uff1a<code>3<\/code><\/li>\n\n\n\n<li>\u89e3\u91ca\uff1a\u6700\u957f\u5b50\u4e32\u662f&nbsp;<code>\"wke\"<\/code>\uff0c\u957f\u5ea6\u4e3a&nbsp;<code>3<\/code>\u3002<br><strong>\u6ce8\u610f<\/strong>\uff1a<code>\"pwke\"<\/code>&nbsp;\u662f\u4e00\u4e2a<strong>\u5b50\u5e8f\u5217<\/strong>\uff0c\u4e0d\u662f\u5b50\u4e32\uff0c\u56e0\u6b64\u4e0d\u6ee1\u8db3\u6761\u4ef6\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u793a\u4f8b 4\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8f93\u5165\uff1a<code>s = \"\"<\/code><\/li>\n\n\n\n<li>\u8f93\u51fa\uff1a<code>0<\/code><\/li>\n\n\n\n<li>\u89e3\u91ca\uff1a\u7a7a\u5b57\u7b26\u4e32\uff0c\u957f\u5ea6\u4e3a&nbsp;<code>0<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\u26a0\ufe0f \u63d0\u793a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>0 &lt;= s.length &lt;= 5 \u00d7 10\u2074<\/code><\/li>\n\n\n\n<li><code>s<\/code>&nbsp;\u7531\u82f1\u6587\u5b57\u6bcd\u3001\u6570\u5b57\u3001\u7b26\u53f7\u548c\u7a7a\u683c\u7ec4\u6210<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\ud83d\udca1 \u89e3\u6cd5\uff1a\u6ed1\u52a8\u7a97\u53e3 + \u54c8\u5e0c\u8868\uff08\u4e00\u6b21\u904d\u5386\uff09\u2014\u2014 O(n) \u65f6\u95f4<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Solution {\n    public int lengthOfLongestSubstring(String s) {\n        Map&lt;Character, Integer> map = new HashMap&lt;>(); \n        int index = 0; \n        int ans = 0;  \n        char&#91;] sArr = s.toCharArray();\n        for (int i = 0; i &lt; sArr.length; i++) {\n            if (map.containsKey(sArr&#91;i])) {\n                index = Math.max(index, map.get(sArr&#91;i]) + 1);\n            }\n            ans = Math.max(ans, i - index + 1);\n            map.put(sArr&#91;i], i);\n        }\n\n        return ans;\n    }\n}<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\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><br>\u5b57\u7b26\u4e32\u53ea\u904d\u5386\u4e00\u6b21\uff0c\u54c8\u5e0c\u8868\u7684 <code>put<\/code> \u548c <code>get<\/code> \u64cd\u4f5c\u5747\u4e3a O(1)\uff0c\u6574\u4f53\u4e3a\u7ebf\u6027\u65f6\u95f4\u3002<\/li>\n\n\n\n<li><strong>\u7a7a\u95f4\u590d\u6742\u5ea6\uff1aO(min(m, n))<\/strong>\n<ul class=\"wp-block-list\">\n<li><code>m<\/code>&nbsp;\u662f\u5b57\u7b26\u96c6\u5927\u5c0f\uff08\u5982 ASCII \u4e3a 128\uff0cUnicode \u66f4\u5927\uff09<\/li>\n\n\n\n<li><code>n<\/code>&nbsp;\u662f\u5b57\u7b26\u4e32\u957f\u5ea6<br>\u54c8\u5e0c\u8868\u6700\u591a\u5b58\u50a8\u4e0d\u540c\u5b57\u7b26\u7684\u6570\u91cf\uff0c\u56e0\u6b64\u7a7a\u95f4\u4e3a\u5b57\u7b26\u96c6\u4e0e\u5b57\u7b26\u4e32\u957f\u5ea6\u7684\u8f83\u5c0f\u503c\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\ud83e\udde9 \u89e3\u9898\u601d\u8def<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u6ed1\u52a8\u7a97\u53e3\u601d\u60f3<\/strong>\uff1a\n<ul class=\"wp-block-list\">\n<li>\u4f7f\u7528\u4e24\u4e2a\u6307\u9488\u7ef4\u62a4\u4e00\u4e2a<strong>\u4e0d\u542b\u91cd\u590d\u5b57\u7b26<\/strong>\u7684\u7a97\u53e3&nbsp;<code>[index, i]<\/code>\u3002<\/li>\n\n\n\n<li><code>i<\/code>&nbsp;\u662f\u53f3\u6307\u9488\uff0c\u4e0d\u65ad\u5411\u53f3\u6269\u5c55\u3002<\/li>\n\n\n\n<li><code>index<\/code>&nbsp;\u662f\u5de6\u6307\u9488\uff0c\u8868\u793a\u5f53\u524d\u65e0\u91cd\u590d\u5b50\u4e32\u7684\u8d77\u59cb\u4f4d\u7f6e\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u54c8\u5e0c\u8868\u8bb0\u5f55\u5b57\u7b26\u4f4d\u7f6e<\/strong>\uff1a\n<ul class=\"wp-block-list\">\n<li>\u7528&nbsp;<code>Map&lt;Character, Integer&gt;<\/code>&nbsp;\u8bb0\u5f55\u6bcf\u4e2a\u5b57\u7b26<strong>\u6700\u540e\u4e00\u6b21\u51fa\u73b0\u7684\u7d22\u5f15<\/strong>\u3002<\/li>\n\n\n\n<li>\u5f53\u9047\u5230\u91cd\u590d\u5b57\u7b26\u65f6\uff0c\u5c06\u5de6\u8fb9\u754c&nbsp;<code>index<\/code>&nbsp;\u79fb\u52a8\u5230<strong>\u8be5\u5b57\u7b26\u4e0a\u6b21\u51fa\u73b0\u4f4d\u7f6e\u7684\u540e\u4e00\u4f4d<\/strong>\uff0c\u786e\u4fdd\u7a97\u53e3\u5185\u65e0\u91cd\u590d\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u5173\u952e\u70b9\uff1a\u5de6\u8fb9\u754c\u4e0d\u56de\u9000<\/strong>\n<ul class=\"wp-block-list\">\n<li>\u4f7f\u7528&nbsp;<code>index = Math.max(index, map.get(sArr[i]) + 1)<\/code>&nbsp;\u800c\u4e0d\u662f\u76f4\u63a5\u8d4b\u503c\u3002<\/li>\n\n\n\n<li>\u9632\u6b62\u5de6\u8fb9\u754c\u201c\u5012\u9000\u201d\uff0c\u4f8b\u5982&nbsp;<code>\"abba\"<\/code>\uff1a\u5f53\u9047\u5230\u7b2c\u4e8c\u4e2a&nbsp;<code>'a'<\/code>&nbsp;\u65f6\uff0c\u5de6\u8fb9\u754c\u5e94\u5728&nbsp;<code>'b'<\/code>&nbsp;\u4e4b\u540e\uff0c\u4e0d\u80fd\u56de\u5230\u7b2c\u4e00\u4e2a&nbsp;<code>'a'<\/code>&nbsp;\u540e\u9762\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u66f4\u65b0\u6700\u5927\u957f\u5ea6<\/strong>\uff1a\n<ul class=\"wp-block-list\">\n<li>\u6bcf\u6b21\u53f3\u6307\u9488\u79fb\u52a8\u540e\uff0c\u8ba1\u7b97\u5f53\u524d\u7a97\u53e3\u957f\u5ea6&nbsp;<code>i - index + 1<\/code>\uff0c\u5e76\u66f4\u65b0&nbsp;<code>ans<\/code>\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u4e3e\u4f8b\u8bf4\u660e<\/strong>\uff1a<br>\u5bf9\u4e8e <code>\"abba\"<\/code>\uff1a\n<ul class=\"wp-block-list\">\n<li><code>i=0<\/code>:&nbsp;<code>'a'<\/code>&nbsp;\u2192 map={a:0}, ans=1<\/li>\n\n\n\n<li><code>i=1<\/code>:&nbsp;<code>'b'<\/code>&nbsp;\u2192 map={a:0,b:1}, ans=2<\/li>\n\n\n\n<li><code>i=2<\/code>:&nbsp;<code>'b'<\/code>&nbsp;\u91cd\u590d \u2192 index = max(0, 1+1)=2, ans=max(2, 2-2+1)=2<\/li>\n\n\n\n<li><code>i=3<\/code>:&nbsp;<code>'a'<\/code>&nbsp;\u91cd\u590d \u2192 index = max(2, 0+1)=2, ans=max(2, 3-2+1)=2<br>\u6700\u7ec8\u7ed3\u679c\u4e3a&nbsp;<code>2<\/code>\uff0c\u5bf9\u5e94\u5b50\u4e32&nbsp;<code>\"ab\"<\/code>&nbsp;\u6216&nbsp;<code>\"ba\"<\/code>\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>\ud83d\udd17 \u65e0\u91cd\u590d\u5b57\u7b26\u7684\u6700\u957f\u5b50\u4e32 \u9898\u76ee\u6765\u6e90\uff1a3. \u65e0\u91cd\u590d\u5b57\u7b26\u7684\u6700\u957f\u5b50\u4e32 &#8211; \u529b\u6263\uff08LeetCode\uff09 \ud83d\udccc  [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[29,12],"tags":[15,24,14],"class_list":["post-143","post","type-post","status-publish","format-standard","hentry","category-sliding_window","category-algorithm","tag-hash","tag-sliding_window","tag-algorithm"],"_links":{"self":[{"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/143","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=143"}],"version-history":[{"count":2,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/143\/revisions"}],"predecessor-version":[{"id":181,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/143\/revisions\/181"}],"wp:attachment":[{"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/media?parent=143"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/categories?post=143"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/tags?post=143"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}