{"id":118,"date":"2025-08-21T18:41:48","date_gmt":"2025-08-21T10:41:48","guid":{"rendered":"https:\/\/heyingnian.com\/?p=118"},"modified":"2025-08-22T16:46:01","modified_gmt":"2025-08-22T08:46:01","slug":"leetcode-128","status":"publish","type":"post","link":"https:\/\/heyingnian.com\/index.php\/2025\/08\/21\/leetcode-128\/","title":{"rendered":"\u6700\u957f\u8fde\u7eed\u5e8f\u5217"},"content":{"rendered":"\n

\ud83d\udd17 \u6700\u957f\u8fde\u7eed\u5e8f\u5217<\/h1>\n\n\n\n
\n

\u9898\u76ee\u6765\u6e90\uff1a128. \u6700\u957f\u8fde\u7eed\u5e8f\u5217 – \u529b\u6263\uff08LeetCode\uff09<\/a><\/a><\/p>\n<\/blockquote>\n\n\n\n

\n\n\n\n

\ud83d\udccc \u9898\u76ee\u63cf\u8ff0<\/h3>\n\n\n\n

\u7ed9\u5b9a\u4e00\u4e2a\u672a\u6392\u5e8f\u7684\u6574\u6570\u6570\u7ec4 nums<\/code>\uff0c\u627e\u51fa\u6570\u5b57\u8fde\u7eed\u7684\u6700\u957f\u5e8f\u5217<\/strong>\uff08\u4e0d\u8981\u6c42\u5e8f\u5217\u5143\u7d20\u5728\u539f\u6570\u7ec4\u4e2d\u8fde\u7eed\uff09\u7684\u957f\u5ea6\u3002<\/p>\n\n\n\n

\u8bf7\u8bbe\u8ba1\u5e76\u5b9e\u73b0\u65f6\u95f4\u590d\u6742\u5ea6\u4e3a O(n)<\/strong> \u7684\u7b97\u6cd5\u89e3\u51b3\u6b64\u95ee\u9898\u3002<\/p>\n\n\n\n

\n\n\n\n

\u2705 \u793a\u4f8b\u89e3\u6790<\/h3>\n\n\n\n

\u793a\u4f8b 1\uff1a<\/strong><\/h4>\n\n\n\n
    \n
  • \u8f93\u5165<\/strong>\uff1anums = [100,4,200,1,3,2]<\/code><\/li>\n\n\n\n
  • \u8f93\u51fa<\/strong>\uff1a4<\/code><\/li>\n\n\n\n
  • \u89e3\u91ca<\/strong>\uff1a\u6700\u957f\u6570\u5b57\u8fde\u7eed\u5e8f\u5217\u662f [1, 2, 3, 4]<\/code>\uff0c\u957f\u5ea6\u4e3a 4\u3002<\/li>\n<\/ul>\n\n\n\n

    \u793a\u4f8b 2\uff1a<\/strong><\/h4>\n\n\n\n
      \n
    • \u8f93\u5165<\/strong>\uff1anums = [0,3,7,2,5,8,4,6,0,1]<\/code><\/li>\n\n\n\n
    • \u8f93\u51fa<\/strong>\uff1a9<\/code><\/li>\n\n\n\n
    • \u89e3\u91ca<\/strong>\uff1a\u6700\u957f\u8fde\u7eed\u5e8f\u5217\u4e3a [0,1,2,3,4,5,6,7,8]<\/code> \u6216 [1,2,3,4,5,6,7,8,9]<\/code>\uff0c\u957f\u5ea6\u4e3a 9\u3002<\/li>\n<\/ul>\n\n\n\n

      \u793a\u4f8b 3\uff1a<\/strong><\/h4>\n\n\n\n
        \n
      • \u8f93\u5165<\/strong>\uff1anums = [1,0,1,2]<\/code><\/li>\n\n\n\n
      • \u8f93\u51fa<\/strong>\uff1a3<\/code><\/li>\n\n\n\n
      • \u89e3\u91ca<\/strong>\uff1a\u6700\u957f\u8fde\u7eed\u5e8f\u5217\u4e3a [0,1,2]<\/code>\uff0c\u6ce8\u610f\u91cd\u590d\u5143\u7d20\u53ea\u7b97\u4e00\u6b21\u3002<\/li>\n<\/ul>\n\n\n\n
        \n\n\n\n

        \u26a0\ufe0f \u63d0\u793a<\/h3>\n\n\n\n
          \n
        • 0 <= nums.length <= 10\u2075<\/code><\/li>\n\n\n\n
        • -10\u2079 <= nums[i] <= 10\u2079<\/code><\/li>\n\n\n\n
        • \u8981\u6c42\u65f6\u95f4\u590d\u6742\u5ea6\uff1aO(n)<\/strong><\/li>\n<\/ul>\n\n\n\n
          \n\n\n\n

          \ud83d\udca1 \u89e3\u6cd5\uff1a\u54c8\u5e0c\u8868 + \u8d77\u70b9\u4f18\u5316\uff08O(n) \u65f6\u95f4\uff09<\/h3>\n\n\n\n
          class<\/strong> Solution<\/strong> {
              public<\/strong> int<\/strong> longestConsecutive<\/strong>(int<\/strong>[] nums) {
                  Set<Integer> numSet = new<\/strong> HashSet<>();
                  for<\/strong> (int<\/strong> num : nums) {
                      numSet.add(num);
                  }

                  int<\/strong> maxLength = 0;

                  for<\/strong> (int<\/strong> num : numSet) {
                      if<\/strong> (!numSet.contains(num - 1)) {
                          int<\/strong> currentNum = num;
                          int<\/strong> currentStreak = 1;
                          while<\/strong> (numSet.contains(currentNum + 1)) {
                              currentNum++;
                              currentStreak++;
                          }

                          maxLength = Math.max(maxLength, currentStreak);
                      }
                  }

                  return<\/strong> maxLength;
              }
          }<\/code><\/pre>\n\n\n\n
          \n\n\n\n
          \ud83d\udcca \u590d\u6742\u5ea6\u5206\u6790<\/h3>\n\n\n\n
            \n
          • \u65f6\u95f4\u590d\u6742\u5ea6<\/strong>\uff1aO(n)\n
              \n
            • \u6bcf\u4e2a\u6570\u5b57\u6700\u591a\u88ab\u8bbf\u95ee\u4e24\u6b21\uff08\u4f5c\u4e3a\u8d77\u70b9\u6216\u88ab\u8df3\u8fc7\uff09\uff0c\u5747\u644a O(1)<\/li>\n<\/ul>\n<\/li>\n\n\n\n
            • \u7a7a\u95f4\u590d\u6742\u5ea6<\/strong>\uff1aO(n)\n
                \n
              • HashSet<\/code> \u5b58\u50a8\u53bb\u91cd\u540e\u7684\u6240\u6709\u5143\u7d20<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n
                \n\n\n\n
                \ud83e\udde9 \u89e3\u9898\u601d\u8def<\/h3>\n\n\n\n
                  \n
                1. \u4f7f\u7528 HashSet<\/code> \u53bb\u91cd\u5e76\u652f\u6301 O(1) \u67e5\u627e<\/strong><\/li>\n\n\n\n
                2. \u5173\u952e\u4f18\u5316\uff1a\u53ea\u4ece\u201c\u8fde\u7eed\u5e8f\u5217\u7684\u8d77\u70b9\u201d\u5f00\u59cb\u7edf\u8ba1<\/strong>\n
                    \n
                  • \u5982\u679c num - 1<\/code> \u5b58\u5728\uff0c\u8bf4\u660e num<\/code> \u4e0d\u662f\u8d77\u70b9\uff0c\u8df3\u8fc7<\/li>\n\n\n\n
                  • \u53ea\u6709\u5f53 num - 1<\/code> \u4e0d\u5b58\u5728\u65f6\uff0c\u624d\u4ee5 num<\/code> \u4e3a\u8d77\u70b9\u5411\u4e0a\u5ef6\u4f38<\/li>\n<\/ul>\n<\/li>\n\n\n\n
                  • \u7edf\u8ba1\u8fde\u7eed\u957f\u5ea6<\/strong>\uff1a\u4ece\u8d77\u70b9\u4e0d\u65ad\u67e5\u627e num+1<\/code>, num+2<\/code>, … \u76f4\u5230\u4e2d\u65ad<\/li>\n\n\n\n
                  • \u66f4\u65b0\u6700\u5927\u957f\u5ea6<\/strong><\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"
                    \ud83d\udd17 \u6700\u957f\u8fde\u7eed\u5e8f\u5217 \u9898\u76ee\u6765\u6e90\uff1a128. \u6700\u957f\u8fde\u7eed\u5e8f\u5217 – \u529b\u6263\uff08LeetCode\uff09 \ud83d\udccc \u9898\u76ee\u63cf\u8ff0 \u7ed9 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22,12],"tags":[15,14],"class_list":["post-118","post","type-post","status-publish","format-standard","hentry","category-hash","category-algorithm","tag-hash","tag-algorithm"],"_links":{"self":[{"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/118","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=118"}],"version-history":[{"count":3,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/118\/revisions"}],"predecessor-version":[{"id":122,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/118\/revisions\/122"}],"wp:attachment":[{"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/media?parent=118"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/categories?post=118"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/tags?post=118"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}