{"id":666,"date":"2025-09-15T10:38:25","date_gmt":"2025-09-15T02:38:25","guid":{"rendered":"https:\/\/reverieland.cn\/?p=666"},"modified":"2025-09-15T10:39:27","modified_gmt":"2025-09-15T02:39:27","slug":"top-k-solution","status":"publish","type":"post","link":"https:\/\/reverieland.cn\/index.php\/666\/","title":{"rendered":"Top-K Solution"},"content":{"rendered":"\n<h3 class=\"wp-block-heading\">1. \u5c0f\u89c4\u6a21 \/ \u4e00\u6b21\u6027\u6279\u91cf\u6570\u636e<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6392\u5e8f + \u622a\u53d6<\/strong>\n<ul class=\"wp-block-list\">\n<li>\u628a\u6240\u6709\u6570\u636e\u6574\u4f53\u6392\u5e8f\uff08\u590d\u6742\u5ea6 O(N log N)\uff09\uff0c\u7136\u540e\u53d6\u524d K \u4e2a\u3002<\/li>\n\n\n\n<li>\u9002\u5408\u4e00\u6b21\u6027\u67e5\u8be2\u3001\u4e0d\u9700\u8981\u9891\u7e41\u66f4\u65b0\u7684\u60c5\u51b5\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">2. \u5927\u89c4\u6a21\u6570\u636e \/ K \u8fdc\u5c0f\u4e8e N<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5806\uff08Heap\uff09<\/strong>\n<ul class=\"wp-block-list\">\n<li>\u7ef4\u62a4\u4e00\u4e2a\u5927\u5c0f\u4e3a K \u7684\u6700\u5c0f\u5806\uff08\u627e\u6700\u5927 K\uff09\u6216\u6700\u5927\u5806\uff08\u627e\u6700\u5c0f K\uff09\u3002<\/li>\n\n\n\n<li>\u63d2\u5165\u6bcf\u4e2a\u5143\u7d20\u65f6\uff1a\n<ul class=\"wp-block-list\">\n<li>\u82e5\u5806\u672a\u6ee1 \u2192 \u76f4\u63a5\u52a0\u5165\uff1b<\/li>\n\n\n\n<li>\u82e5\u5806\u6ee1\u4e14\u65b0\u5143\u7d20\u66f4\u4f18 \u2192 \u66ff\u6362\u5806\u9876\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>\u590d\u6742\u5ea6 O(N log K)\uff0c\u6bd4\u5168\u91cf\u6392\u5e8f\u9ad8\u6548\u3002<\/li>\n\n\n\n<li>\u5e38\u7528\u4e8e\u5b9e\u65f6\u6392\u884c\u699c\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p><strong>\u4e3a\u4ec0\u4e48\u662f\u5c0f\u9876\u5806\uff1f<\/strong><\/p>\n\n\n\n<p>\u56e0\u4e3a\u6211\u4eec\u5e0c\u671b\u6dd8\u6c70\u90a3\u4e9b\u76f8\u5bf9\u8f83\u5c0f\u7684\u5143\u7d20\u3002\u6839\u636e\u5c0f\u9876\u5806\u7684\u5b9a\u4e49\uff0c\u5806\u9876\u59cb\u7ec8\u662f\u5f53\u524d K \u4e2a\u5143\u7d20\u4e2d\u7684\u6700\u5c0f\u503c\u3002<strong>\u5f53\u6211\u4eec\u9047\u5230\u4e00\u4e2a\u6bd4\u8fd9\u4e2a\u6700\u5c0f\u503c\u66f4\u5927\u7684\u65b0\u5143\u7d20\u65f6\uff0c\u5b83\u5c31\u6709\u8d44\u683c\u8fdb\u5165\u524d K \u540d\u3002<\/strong>\u8fd9\u65f6\uff0c\u6211\u4eec\u53ef\u4ee5\u7528\u65b0\u5143\u7d20\u66ff\u6362\u6389\u5f53\u524d\u6700\u5c0f\u7684\u5143\u7d20\uff0c\u5e76\u91cd\u65b0\u8c03\u6574\u5806\u3002\u8fd9\u6837\uff0c\u5806\u4e2d\u59cb\u7ec8\u4fdd\u6301\u7740\u6700\u5927\u7684 K \u4e2a\u5143\u7d20\u3002<\/p>\n\n\n\n<p>\u5982\u679c\u6211\u4eec\u8981\u627e\u6700\u5c0f\u7684 K \u4e2a\u5143\u7d20\uff0c\u5219\u4f7f\u7528\u540c\u6837\u7684\u65b9\u6cd5\uff0c\u4f46\u6784\u5efa\u4e00\u4e2a<strong>\u5927\u9876\u5806<\/strong>\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\u9664\u4e86\u5806\uff0c\u8fd8\u6709\u4e00\u4e9b\u5176\u4ed6\u65b9\u6cd5\u53ef\u4ee5\u89e3\u51b3 Top-K \u95ee\u9898\uff0c\u4f46\u5b83\u4eec\u901a\u5e38\u5728\u7279\u5b9a\u573a\u666f\u4e0b\u4f7f\u7528\uff0c\u6216\u8005\u6548\u7387\u4e0d\u5982\u5806\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5feb\u901f\u9009\u62e9\uff08Quickselect\uff09<\/strong>\uff1a\n<ul class=\"wp-block-list\">\n<li>\u8fd9\u662f\u4e00\u79cd\u57fa\u4e8e\u5feb\u901f\u6392\u5e8f\uff08Quicksort\uff09\u7684\u5206\u6cbb\u7b97\u6cd5\uff0c\u4f46\u53ea\u5904\u7406\u4e00\u8fb9\u7684\u5206\u533a\u3002<\/li>\n\n\n\n<li>\u5b83\u7684\u5e73\u5747\u65f6\u95f4\u590d\u6742\u5ea6\u662f O(N)\uff0c\u6bd4\u5806\u7684 O(N log K) \u66f4\u597d\uff0c\u4f46\u5728\u6700\u574f\u60c5\u51b5\u4e0b\u53ef\u80fd\u9000\u5316\u5230 O(N^2)\u3002<\/li>\n\n\n\n<li>\u5b83\u901a\u5e38\u7528\u4e8e<strong>\u79bb\u7ebf<\/strong>\uff08\u6240\u6709\u6570\u636e\u4e00\u6b21\u6027\u53ef\u7528\uff09\u4e14\u4e0d\u9700\u8981<strong>\u6301\u7eed\u7ef4\u62a4<\/strong>\u7684\u573a\u666f\u3002<\/li>\n\n\n\n<li>\u5b9e\u73b0\u8d77\u6765\u6bd4\u5806\u590d\u6742\uff0c\u4e14\u4e0d\u5982\u5806\u7a33\u5b9a\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u8ba1\u6570\u6392\u5e8f\u6216\u6876\u6392\u5e8f\uff08Counting Sort \/ Bucket Sort\uff09<\/strong>\uff1a\n<ul class=\"wp-block-list\">\n<li>\u5982\u679c\u6570\u636e\u7684\u8303\u56f4\u6709\u9650\u4e14\u76f8\u5bf9\u8f83\u5c0f\uff0c\u53ef\u4ee5\u4f7f\u7528\u8fd9\u4e9b\u7ebf\u6027\u65f6\u95f4\u590d\u6742\u5ea6\u7684\u6392\u5e8f\u7b97\u6cd5\u3002<\/li>\n\n\n\n<li>\u5b83\u4eec\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u662f O(N + M)\uff0c\u5176\u4e2d M \u662f\u6570\u636e\u8303\u56f4\u3002<\/li>\n\n\n\n<li>\u8fd9\u79cd\u65b9\u6cd5\u6709\u5f88\u5f3a\u7684\u5c40\u9650\u6027\uff0c\u4e0d\u9002\u7528\u4e8e\u6570\u636e\u8303\u56f4\u975e\u5e38\u5927\u6216\u6570\u636e\u7c7b\u578b\u4e3a\u6d6e\u70b9\u6570\u7684\u60c5\u51b5\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<h3 class=\"wp-block-heading\">3. \u5206\u5e03\u5f0f\/\u5927\u6570\u636e\u573a\u666f<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>MapReduce \/ \u5206\u5e03\u5f0f Top-K<\/strong> <mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-cyan-blue-color\">\uff08\u5206\u6cbb\u7684\u601d\u60f3\uff09<\/mark>\n<ul class=\"wp-block-list\">\n<li>\u6bcf\u4e2a\u5206\u7247\u5148\u7b97\u51fa\u5c40\u90e8 Top-K\uff1b<\/li>\n\n\n\n<li>\u6c47\u603b\u540e\u518d\u53d6\u5168\u5c40 Top-K\u3002<\/li>\n\n\n\n<li>\u5927\u5e45\u51cf\u5c11\u901a\u4fe1\u548c\u5185\u5b58\u538b\u529b\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">4.\u62d3\u5c55\u5ef6\u4f38<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"h_441597621_22\"><strong>1. \u4ece\u5341\u4ebf\u6570\u636e\u4e2d\u627e\u5230\u51fa\u73b0\u6b21\u6570\u6700\u591a\u7684\u5341\u4e2a\u6570\u5b57<\/strong><\/h4>\n\n\n\n<p>\u7528hash\u6811\u8bb0\u5f55\u6bcf\u4e2a\u6570\u5b57\u51fa\u73b0\u7684\u9891\u7387\uff0c\u8f6c\u5316\u4e3a\u5728\u5404\u4e2a\u6570\u5b57\u7684\u9891\u7387\u4e2d\u627e\u5230Top K\u7684\u95ee\u9898\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"h_441597621_23\"><strong>2. \u4ece\u5341\u4ebf\u6570\u636e\u4e2d\u627e\u5230\u5347\u5e8f\u7684\u7b2c\u4e03\u4ebf\u4e2a\u6570<\/strong><\/h4>\n\n\n\n<p><strong>2.1 \u5feb\u901f\u6392\u5e8f<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>step1\uff1a\u4ee5\u6570\u7ec4\u6700\u540e\u4e00\u4e2a\u5143\u7d20\u4f5c\u4e3a\u57fa\u51c6\u503c\uff0c\u5c06\u6570\u636epartition\u4e3a<code>[left,mid-1]<\/code>\u548c<code>[mid,right]<\/code>\u4e24\u4e2a\u533a\u95f4\uff0c\u5176\u4e2d<code>[left,mid-1]<\/code>\u7684\u6570\u90fd\u5c0f\u4e8ebase\u503c\uff0c<code>[mid,right]<\/code>\u90fd\u5927\u4e8e\u7b49\u4e8ebase\u503c<\/li>\n\n\n\n<li>step2\uff1a\u8ba1\u7b97<code>[mid, right]<\/code>\u6570\u7ec4\u957f\u5ea6L\uff1a\n<ul class=\"wp-block-list\">\n<li>\u5982\u679cL\u7b49\u4e8e\u4e09\u4ebf\uff0c\u90a3\u4e48<code>[left,mid-1]<\/code>\u4e2d\u7684\u4e03\u4ebf\u4e2a\u6570\u5b57\u5c0f\u4e8e<code>[mid,right]<\/code>\u4e2d\u7684\u4e09\u4ebf\u4e2a\u6570\u5b57\uff0c\u53ea\u9700\u8981\u5728<code>[left,mid-1]<\/code>\u4e2d\u627e\u5230\u6700\u5927\u503c\u5373\u53ef<\/li>\n\n\n\n<li>\u5982\u679cL\u5927\u4e8e\u4e09\u4ebf\uff0c\u5219\u5c06\u95ee\u9898\u8f6c\u5316\u4e3a\u5728<code>[mid, right]<\/code>\u4e2d\u627e\u5230\u7b2c\uff08L-\u4e09\u4ebf\uff09\u4e2a\u6570<\/li>\n\n\n\n<li>\u5982\u679cL\u5c0f\u4e8e\u4e09\u4ebf\u5219\u95ee\u9898\u8fd8\u662f\u5728<code>[left,mid-1]<\/code>\u4e2d\u627e\u5230\u7b2c\u4e03\u4ebf\u5927\u7684\u6570<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><em>\u5728step2\u4e2d\uff0c\u5982\u679c\u6570\u636e\u91cf\u7ea7\u8db3\u591f\u5c0f\u5219\u53ef\u4ee5\u76f4\u63a5\u8fdb\u884c\u6392\u5e8f\u5f97\u5230\u7b54\u6848\u3002<\/em><\/p>\n<\/blockquote>\n\n\n\n<p><strong>2.2 \u6876\u6392\u5e8f<\/strong><\/p>\n\n\n\n<p>\u5047\u5982\u6570\u636e\u7684\u8303\u56f4\u662f\u6709\u9650\u7684\uff08\u6709\u6700\u5927\u503c\u548c\u6700\u5c0f\u503c\uff09\u4e14\u8f83\u5747\u5300\u5206\u5e03\uff0c\u90a3\u4e48\u4f7f\u7528\u6876\u6392\u5e8f\u53ef\u4ee5\u8fdb\u4e00\u6b65\u63d0\u5347\u6548\u7387\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>step1\uff1a\u83b7\u53d6\u6570\u636e\u7684max\u548cmin<\/li>\n\n\n\n<li>step2\uff1a\u5c06\u6240\u6709\u7684n\u4efd\u6570\u636e\u5206\u5230m\u4e2a\u6587\u4ef6\u4e2d\uff0c\u540c\u65f6\u8bb0\u5f55\u6bcf\u4efd\u5b50\u6587\u4ef6\u4e2d\u7684\u6570\u636e\u91cf<\/li>\n\n\n\n<li>step3\uff1a\u4ece\u5c0f\u5230\u5927\u7d2f\u52a0\u6587\u4ef6\u6570\u636e\u91cf\uff0c\u627e\u5230\u7b2c\u4e03\u4ebf\u4e2a\u6570\u6240\u5728\u7684\u6587\u4ef6\uff0c\u8bb0\u5f55\u524d\u9762\u6587\u4ef6\u7684\u603b\u6570\u636e\u91cfcount<\/li>\n\n\n\n<li>step4\uff1a\u5c06\u95ee\u9898\u8f6c\u5316\u4e3a\u5728\u7b2c\u4e03\u4ebf\u4e2a\u6570\u6240\u5728\u7684\u6587\u4ef6\u4e2d\u5bfb\u627e\u7b2c\uff08\u4e03\u4ebf-count\uff09\u4e2a\u6570<\/li>\n<\/ul>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><em>\u5728step4\u4e2d\uff0c\u5982\u679c\u5185\u5b58\u8db3\u591f\u5b58\u653e\u6240\u6709\u6570\u636e\uff0c\u53ef\u4ee5\u76f4\u63a5\u6392\u5e8f\u83b7\u53d6\u7b2c\u4e03\u4ebf\u4e2a\u6570\u5b57\u3002<\/em><\/p>\n<\/blockquote>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"h_441597621_24\"><strong>3. \u5bf9\u5341\u4ebf\u6570\u636e\u8fdb\u884c\u6392\u5e8f<\/strong>\uff1a\u591a\u8def\u5f52\u5e76\u6392\u5e8f<\/h4>\n","protected":false},"excerpt":{"rendered":"<p>1. \u5c0f\u89c4\u6a21 \/ \u4e00\u6b21\u6027\u6279\u91cf\u6570\u636e 2. \u5927\u89c4\u6a21\u6570\u636e \/ K \u8fdc\u5c0f\u4e8e N \u4e3a\u4ec0\u4e48\u662f\u5c0f\u9876\u5806\uff1f \u56e0\u4e3a\u6211\u4eec\u5e0c\u671b\u6dd8\u6c70\u90a3\u4e9b\u76f8\u5bf9\u8f83\u5c0f\u7684\u5143\u7d20\u3002\u6839\u636e &#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","emotion":"","emotion_color":"","title_style":"","license":"","footnotes":""},"categories":[15],"tags":[42],"class_list":["post-666","post","type-post","status-publish","format-standard","hentry","category-algorithm","tag-42"],"_links":{"self":[{"href":"https:\/\/reverieland.cn\/index.php\/wp-json\/wp\/v2\/posts\/666","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/reverieland.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/reverieland.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/reverieland.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/reverieland.cn\/index.php\/wp-json\/wp\/v2\/comments?post=666"}],"version-history":[{"count":1,"href":"https:\/\/reverieland.cn\/index.php\/wp-json\/wp\/v2\/posts\/666\/revisions"}],"predecessor-version":[{"id":667,"href":"https:\/\/reverieland.cn\/index.php\/wp-json\/wp\/v2\/posts\/666\/revisions\/667"}],"wp:attachment":[{"href":"https:\/\/reverieland.cn\/index.php\/wp-json\/wp\/v2\/media?parent=666"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/reverieland.cn\/index.php\/wp-json\/wp\/v2\/categories?post=666"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/reverieland.cn\/index.php\/wp-json\/wp\/v2\/tags?post=666"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}