\ud83d\udccc \u9898\u76ee\u63cf\u8ff0<\/p>\n\n\n\n
\u7ed9\u4f60\u94fe\u8868\u7684\u5934\u8282\u70b9 \u8981\u6c42\uff1a<\/p>\n\n\n\n \u2705 \u793a\u4f8b\u89e3\u6790<\/p>\n\n\n\n \u793a\u4f8b 1\uff1a<\/p>\n\n\n\n \u8f93\u5165\uff1a \u793a\u4f8b 2\uff1a<\/p>\n\n\n\n \u8f93\u5165\uff1a \u26a0\ufe0f \u63d0\u793a<\/p>\n\n\n\n \ud83d\udca1 \u89e3\u6cd5\uff1a\u5206\u7ec4\u53cd\u8f6c + \u865a\u62df\u5934\u8282\u70b9 \u2014\u2014 O(n) \u65f6\u95f4\uff0cO(1) \u7a7a\u95f4<\/p>\n\n\n\n \ud83d\udcca \u590d\u6742\u5ea6\u5206\u6790<\/p>\n\n\n\n \ud83e\udde9 \u89e3\u9898\u601d\u8def<\/p>\n\n\n\n \u6838\u5fc3\u601d\u60f3\uff1a\u5206\u7ec4\u5207\u5272 + \u5c40\u90e8\u53cd\u8f6c + \u91cd\u65b0\u62fc\u63a5<\/strong><\/p>\n\n\n\n \u4e3e\u4f8b\u8bf4\u660e\uff1a<\/p>\n\n\n\n \u8f93\u5165\uff1a \u8fb9\u754c\u5904\u7406\uff1a<\/p>\n\n\n\n \ud83d\udd17 K \u4e2a\u4e00\u7ec4\u7ffb\u8f6c\u94fe\u8868 \u9898\u76ee\u6765\u6e90\uff1a25. K \u4e2a\u4e00\u7ec4\u7ffb\u8f6c\u94fe\u8868 – \u529b\u6263\uff08LeetCode\uff09 \ud83d\udccc \u9898 […]<\/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":[14,51],"class_list":["post-389","post","type-post","status-publish","format-standard","hentry","category-algorithm","category-linked_list","tag-algorithm","tag-linked_list"],"_links":{"self":[{"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/389","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=389"}],"version-history":[{"count":1,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/389\/revisions"}],"predecessor-version":[{"id":392,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/389\/revisions\/392"}],"wp:attachment":[{"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/media?parent=389"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/categories?post=389"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/tags?post=389"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}head<\/code>\uff0c\u6bcf k \u4e2a\u8282\u70b9\u4e00\u7ec4\u8fdb\u884c\u7ffb\u8f6c<\/strong>\uff0c\u8bf7\u4f60\u8fd4\u56de\u4fee\u6539\u540e\u7684\u94fe\u8868\u3002<\/p>\n\n\n\n\n
k<\/code>\u00a0\u662f\u4e00\u4e2a\u6b63\u6574\u6570\uff0c\u4e14\u00a0k <= \u94fe\u8868\u957f\u5ea6<\/code><\/li>\n\n\n\nk<\/code>\u00a0\u7684\u6574\u6570\u500d\uff0c\u6700\u540e\u5269\u4f59\u7684\u8282\u70b9\u4fdd\u6301\u539f\u6709\u987a\u5e8f<\/strong><\/li>\n\n\n\n![\"\"](\"https:\/\/heyingnian.com\/wp-content\/uploads\/2025\/09\/image-25.png\")
<\/div><\/figure>\n\n\n\nhead = [1,2,3,4,5]<\/code>, k = 2<\/code>
\u8f93\u51fa\uff1a[2,1,4,3,5]<\/code>
\u89e3\u91ca\uff1a\u524d\u4e24\u7ec4 [1,2] \u2192 [2,1]<\/code>\uff0c[3,4] \u2192 [4,3]<\/code>\uff0c\u5269\u4f59 [5]<\/code> \u4e0d\u8db3 k=2\uff0c\u4fdd\u6301\u539f\u5e8f\u3002<\/p>\n\n\n\n![\"\"](\"https:\/\/heyingnian.com\/wp-content\/uploads\/2025\/09\/image-26.png\")
<\/div><\/figure>\n\n\n\nhead = [1,2,3,4,5]<\/code>, k = 3<\/code>
\u8f93\u51fa\uff1a[3,2,1,4,5]<\/code>
\u89e3\u91ca\uff1a\u7b2c\u4e00\u7ec4 [1,2,3] \u2192 [3,2,1]<\/code>\uff0c\u5269\u4f59 [4,5]<\/code> \u4e0d\u8db3 k=3\uff0c\u4fdd\u6301\u539f\u5e8f\u3002<\/p>\n\n\n\n\n
n<\/code><\/li>\n\n\n\n1 <= k <= n <= 5000<\/code><\/li>\n\n\n\n0 <= Node.val <= 1000<\/code><\/li>\n<\/ul>\n\n\n\nclass Solution {\n public ListNode reverseKGroup(ListNode head, int k) {\n ListNode dummy = new ListNode(0);\n dummy.next = head;\n ListNode pre = dummy;\n ListNode end = dummy;\n\n while (end != null) {\n \/\/ 1. \u5b9a\u4f4d\u5f53\u524d\u7ec4\u7684\u5c3e\u8282\u70b9 end\n for (int i = 0; i < k && end != null; i++) {\n end = end.next;\n }\n if (end == null) break; \/\/ \u4e0d\u8db3 k \u4e2a\uff0c\u7ed3\u675f\n\n \/\/ 2. \u4fdd\u5b58\u4e0b\u4e00\u7ec4\u7684\u8d77\u70b9\n ListNode nextGroupStart = end.next;\n end.next = null; \/\/ \u4e34\u65f6\u65ad\u5f00\uff0c\u4fbf\u4e8e\u53cd\u8f6c\n\n \/\/ 3. \u53cd\u8f6c\u5f53\u524d\u7ec4 [start ... end]\n ListNode start = pre.next;\n pre.next = reverse(start); \/\/ \u63a5\u4e0a\u53cd\u8f6c\u540e\u7684\u5934\n\n \/\/ 4. \u5c06\u539f\u7ec4\u5934\uff08\u73b0\u7ec4\u5c3e\uff09\u8fde\u5230\u4e0b\u4e00\u7ec4\n start.next = nextGroupStart;\n\n \/\/ 5. \u66f4\u65b0 pre \u548c end\uff0c\u51c6\u5907\u4e0b\u4e00\u8f6e\n pre = start;\n end = start;\n }\n\n return dummy.next;\n }\n\n \/\/ \u53cd\u8f6c\u94fe\u8868\uff0c\u8fd4\u56de\u65b0\u5934\u8282\u70b9\n public ListNode reverse(ListNode head) {\n ListNode p = null;\n while (head != null) {\n ListNode next = head.next;\n head.next = p;\n p = head;\n head = next;\n }\n return p;\n }\n}<\/code><\/pre>\n\n\n\n\n
\n
\n
\n
\n
dummy<\/code>\uff0c\u6307\u5411\u00a0head<\/code>\u3002<\/li>\n\n\n\npre<\/code>\u00a0\u6307\u5411\u5f53\u524d\u7ec4\u7684\u524d\u9a71\u8282\u70b9<\/strong>\uff08\u521d\u59cb\u4e3a\u00a0dummy<\/code>\uff09\u3002<\/li>\n\n\n\nend<\/code>\u00a0\u7528\u4e8e\u5b9a\u4f4d\u5f53\u524d\u7ec4\u7684\u5c3e\u8282\u70b9<\/strong>\uff08\u521d\u59cb\u4e5f\u4e3a\u00a0dummy<\/code>\uff09\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\nend<\/code>\u00a0\u4ece\u5f53\u524d\u4f4d\u7f6e\u524d\u8fdb\u00a0k<\/code>\u00a0\u6b65\u3002<\/li>end == null<\/code>\u00a0\u2192 \u8bf4\u660e\u4e0d\u8db3\u00a0k<\/code>\u00a0\u4e2a \u2192 \u76f4\u63a5\u9000\u51fa\u3002<\/li><\/ul>b. \u65ad\u5f00\u5f53\u524d\u7ec4<\/strong>\uff1anextGroupStart = end.next<\/code>\uff08\u4e0b\u4e00\u7ec4\u8d77\u70b9\uff09\u3002<\/li>end.next = null<\/code>\u00a0\u2192 \u4e34\u65f6\u65ad\u5f00\u5f53\u524d\u7ec4\uff0c\u4fbf\u4e8e\u72ec\u7acb\u53cd\u8f6c\u3002<\/li><\/ul>c. \u53cd\u8f6c\u5f53\u524d\u7ec4<\/strong>\uff1astart = pre.next<\/code>\uff08\u5f53\u524d\u7ec4\u5934\uff09<\/li>pre.next = reverse(start)<\/code>\u00a0\u2192 \u5c06\u53cd\u8f6c\u540e\u7684\u65b0\u5934\u63a5\u56de\u4e3b\u94fe\u3002<\/li><\/ul>d. \u62fc\u63a5\u4e0b\u4e00\u7ec4<\/strong>\uff1astart<\/code>\u00a0\u8282\u70b9\uff08\u73b0\u5728\u662f\u7ec4\u5c3e\uff09 \u2192\u00a0start.next = nextGroupStart<\/code><\/li><\/ul>e. \u66f4\u65b0\u6307\u9488<\/strong>\uff1a\n\n
pre = start<\/code>\uff08\u5f53\u524d\u7ec4\u5c3e\u6210\u4e3a\u4e0b\u4e00\u7ec4\u7684\u524d\u9a71\uff09<\/li>\n\n\n\nend = start<\/code>\uff08\u540c\u6b65\u4f4d\u7f6e\uff0c\u51c6\u5907\u4e0b\u4e00\u8f6e\u524d\u8fdb\uff09<\/li>\n<\/ul>\n<\/li>\n\n\n\n\n
dummy.next<\/code>\u00a0\u4e3a\u6700\u7ec8\u94fe\u8868\u5934\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\nhead = [1,2,3,4,5]<\/code>, k = 2<\/code><\/p>\n\n\n\n\u521d\u59cb\uff1adummy \u2192 1 \u2192 2 \u2192 3 \u2192 4 \u2192 5
pre^ end^
\u7b2c1\u8f6e\uff1a
end \u524d\u8fdb2\u6b65 \u2192 end \u6307\u5411 2
\u65ad\u5f00\uff1a2.next = null \u2192 [1\u21922] \u4e0e [3\u21924\u21925] \u5206\u79bb
\u53cd\u8f6c [1\u21922] \u2192 [2\u21921]
pre.next = 2 \u2192 dummy\u21922\u21921
1.next = 3 \u2192 1\u21923\u21924\u21925
\u66f4\u65b0\uff1apre = 1, end = 1
\u5f53\u524d\uff1adummy \u2192 2 \u2192 1 \u2192 3 \u2192 4 \u2192 5
pre^ end^
\u7b2c2\u8f6e\uff1a
end \u524d\u8fdb2\u6b65 \u2192 end \u6307\u5411 4
\u65ad\u5f00\uff1a4.next = null \u2192 [3\u21924] \u4e0e [5] \u5206\u79bb
\u53cd\u8f6c [3\u21924] \u2192 [4\u21923]
pre.next = 4 \u2192 1\u21924\u21923
3.next = 5 \u2192 3\u21925
\u66f4\u65b0\uff1apre = 3, end = 3
\u5f53\u524d\uff1adummy \u2192 2 \u2192 1 \u2192 4 \u2192 3 \u2192 5
pre^ end^
\u7b2c3\u8f6e\uff1a
end \u524d\u8fdb2\u6b65\uff1a\u7b2c\u4e00\u6b65 end=5\uff0c\u7b2c\u4e8c\u6b65 end=null \u2192 break
\u6700\u7ec8\uff1a[2,1,4,3,5] \u2705<\/code><\/pre>\n\n\n\n\n