{"id":294,"date":"2022-07-31T18:27:31","date_gmt":"2022-07-31T10:27:31","guid":{"rendered":"https:\/\/blog.cirno.fun\/?p=294"},"modified":"2024-09-12T09:36:17","modified_gmt":"2024-09-12T01:36:17","slug":"%e6%95%b4%e6%95%b0%e4%ba%8c%e5%88%86-%e6%af%94%e6%83%b3%e8%b1%a1%e4%b8%ad%e7%9a%84%e9%9a%be","status":"publish","type":"post","link":"https:\/\/blog.sssn.tech\/?p=294","title":{"rendered":"\u6574\u6570\u4e8c\u5206\u2014\u2014\u6bd4\u60f3\u8c61\u4e2d\u7684\u96be"},"content":{"rendered":"

\uff08y\u603b\u592a\u5f3a\u529borz\uff09 \u6765\u770b\u4e00\u9053\u8fd9\u6837\u7684\u9898\uff1a \u7ed9\u51fa\u4e00\u4e2a\u5355\u8c03\u4e0d\u51cf\u6570\u5217\uff0c\u5bf9\u8fd9\u4e2a\u6570\u5217\u63d0\u51faq\u6b21\u95ee\u8be2\uff0c\u6bcf\u4e00\u6b21\u95ee\u8be2\u7ed9\u51fa\u4e00\u4e2a\u6570\u5217\u4e2d\u7684\u5143\u7d20x\uff0c\u6c42\uff1a<\/p>\n

    \n
  1. \u7b2c\u4e00\u4e2a\u5927\u4e8ex\u7684\u5143\u7d20<\/li>\n
  2. \u7b2c\u4e00\u4e2a\u5927\u4e8e\u7b49\u4e8ex\u7684\u5143\u7d20<\/li>\n
  3. \u6700\u540e\u4e00\u4e2a\u5c0f\u4e8ex\u7684\u5143\u7d20<\/li>\n
  4. \u6700\u540e\u4e00\u4e2a\u5c0f\u4e8e\u7b49\u4e8ex\u7684\u5143\u7d20<\/li>\n<\/ol>\n

    \u6574\u6570\u4e8c\u5206\u5f80\u5f80\u9762\u4e34\u7740\u975e\u5e38\u590d\u6742\u7684\u4e34\u754c\u60c5\u51b5\u548c\u8fb9\u754c\u5224\u65ad\u95ee\u9898\uff0c\u8fd9\u4fbf\u662f\u5176\u86cb\u75bc\u7684\u60c5\u51b5\uff0c\u7f51\u4e0a\u5bf9\u4e8e\u8fd9\u4e00\u7c7b\u95ee\u9898\u6709\u591a\u79cd\u5199\u6cd5\uff0c\u6211\u4ecb\u7ecd\u4e24\u79cd\u8f83\u4e3a\u597d\u7406\u89e3\u7684\uff0c\u8fd9\u7bc7\u662f\u5176\u4e2d\u4e4b\u4e00\uff0c\u5373yxc\u5927\u795e\u7684\u4e8c\u5206\u6a21\u677f<\/p>\n

    \/\/1\nwhile(L<R){\n    mid=L+R>>1;\n    if(check(mid))\n        L=mid+1;\n    else    R=mid;\n}\n\/\/2\nwhile(L<R){\n    mid=L+R+1>>1;\n    if(check(mid))\n        R=mid-1;\n    else    L=mid;\n}<\/code><\/pre>\n
    \u8fd9\u4e24\u79cd\u6a21\u677f\u7684\u533a\u522b\u4e3b\u8981\u5728\u4e8e\u53d6mid\u65f6\u5411\u4e0a\u8fd8\u662f\u5411\u4e0b\uff0c\u548c\u5728\u4e8c\u5206\u65f6\u7f29\u5c0fR\u8fb9\u754c\u8fd8\u662f\u7f29\u5c0fL\u8fb9\u754c \u5148\u8bf4\u7ed3\u8bba\uff1a\u7f29\u5c0fL\u8fb9\u754c\u65f6\uff0cmid\u5411\u4e0b\u53d6\u6574\uff0c\u7f29\u5c0fR\u8fb9\u754c\u65f6\uff0cmid\u5411\u4e0a\u53d6\u6574<\/strong>\u8fd9\u4e3b\u8981\u662f\u907f\u514d\u4e00\u7c7b\u95ee\u9898\uff0c\u8bf7\u770b\/\/2<\/code>\u7684\u4ee3\u7801\uff1a\u5f53L=R-1\u65f6\uff0cmid\u672c\u5e94\u5411\u4e0a\u53d6\u6574\u5230R\uff0c\u4f46\u662f\u5982\u679c\u6f0f\u52a0\u4e861\uff0c\u5219\u4f1a\u53d8\u6210\u5411\u4e0b\u53d6\u6574\u7684L\uff0c\u6b64\u65f6\u5982\u679ccheck\u4e3afalse\uff0c\u6267\u884cL=mid<\/code>\uff0c\u533a\u95f4\u6ca1\u6709\u53d8\uff0c\u5c31\u4f1a\u9677\u5165\u6b7b\u5faa\u73af<\/p>\n
    \u6211\u4eec\u5c06\u4e8c\u5206\u53ef\u4ee5\u7406\u89e3\u4e3a\u4e00\u4e2a\u533a\u95f4\u7684\u67d3\u8272\u95ee\u9898\uff0c\u5bf9\u4e8e\u4e00\u4e2a\u7ea2\u84dd\u4e24\u8272\u7684\u533a\u95f4\uff0c\u6211\u4eec\u5e0c\u671b\u627e\u51fa\u7ea2\u84dd\u5206\u754c\u70b9\u2014\u2014\u6ce8\u610f\uff0c\u6574\u6570\u4e8c\u5206\u4e2d\uff0c\u7ea2\u84dd\u5206\u754c\u70b9\u662f\u4e0d\u540c\u7684\uff0c\u5373\u7ea2\u8272\u672b\u5c3e\u548c\u84dd\u8272\u5f00\u5934\u4e0d\u662f\u4e00\u4e2a\u4f4d\u7f6e \"file\"\u5728\u5f00\u59cb\u64cd\u4f5c\u524d\uff0c\u6211\u4eec\u8ba4\u4e3a\u6574\u4e2a\u7ebf\u6bb5\u90fd\u662f\u7070\u8272\u7684 \u6bcf\u6b21\u53d6\u5f97\u4e00\u70b9mid\u65f6\uff0c\u5982\u679cmid\u662f\u7ea2\u8272\uff0c\u5219\u53ef\u4ee5\u5f97\u51famid\u53c8\u4fa7\u5168\u90e8\u662f\u7ea2\u8272\uff0c\u800c\u5982\u679c\u662f\u84dd\u8272\uff0c\u5219\u53ef\u4ee5\u5f97\u51famid\u4ee5\u5de6\u5168\u662f\u84dd\u8272\uff0c\u8fd9\u6837\u6211\u4eec\u5c31\u53ef\u4ee5\u4ee5logN<\/code>\u7684\u6548\u7387\u5feb\u901f\u67d3\u8272<\/p>\n
    \u800cL\uff0cR\u7684\u8c03\u6574\u53d6\u51b3\u4e8e\u6211\u4eec\u8981\u6c42\u7684\u95ee\u9898\u2014\u2014\u662f\u84dd\u8272\u672b\u5c3e\uff1f\u7ea2\u8272\u5f00\u5934\uff1f \u6211\u4eec\u4ee5\u67e5\u8be2\u7ea2\u8272\u5f00\u5934\u4e3a\u4f8b\uff1a \u5728\u6bcf\u4e00\u6b21\u53d6\u5f97mid\u65f6\uff0c\u90fd\u5e94\u67e5\u8be2a[mid]\u7684\u989c\u8272 \u5982\u679c\u4e3a\u84dd\u8272\uff0c\u5219L=mid+1\uff0c\u4e3a\u4ec0\u4e48\u52a01\uff1fmid\u4e0d\u53ef\u80fd\u662f\u7b54\u6848\uff0c\u6211\u4eec\u8981\u7f29\u5c0f\u6240\u67e5\u8be2\u7684\u8303\u56f4 \u5982\u679c\u4e3a\u7ea2\u8272\uff0c\u6b64\u65f6\u5e94\u8be5R=mid,\u6b64\u65f6\u4e0d\u51cf1\u7684\u7406\u7531\u662f\uff0c\u56e0\u4e3a\u6211\u4eec\u60f3\u67e5\u8be2\u7ea2\u8272\u5f00\u5934\uff0c\u6b64\u65f6\u7684mid\u53ef\u80fd\u662f\u7b54\u6848\uff0c\u4e0d\u80fd\u6f0f\u6389\u4e86 \u800c\u5728\u6211\u4eec\u6839\u636e\u95ee\u9898\u786e\u5b9a\u597d\u533a\u95f4\u53d8\u5316\u65f6\uff0cmid\u7684\u53d6\u6574\u89c4\u5219\u4e5f\u968f\u4e4b\u786e\u5b9a\u4e86\uff0c\u6b64\u65f6\u95ee\u9898\u5f97\u5230\u89e3\u51b3<\/p>\n
    \u7b80\u800c\u8a00\u4e4b\uff1a<\/p>\n
      \n
    1. \u786e\u5b9a\u95ee\u9898<\/li>\n
    2. \u5199\u51faL\uff0cR\u53d8\u5316\u89c4\u5219<\/li>\n
    3. \u6839\u636eL\uff0cR\u7684\u53d8\u5316\u786e\u5b9amid\u53d6\u6574\u89c4\u5219<\/li>\n<\/ol>\n
      \u4ee5\u4e0a\u4e09\u6b65\u5927\u6982\u53ef\u4ee5\u89e3\u51b3\u5927\u90e8\u5206\u4e8c\u5206\u95ee\u9898\u4e86\u5427 \u8d34\u4e0a\u539f\u95ee\u9898\u7684\u4ee3\u7801:<\/p>\n
      #include<bits\/stdc++.h>\nusing namespace std;\n\nconst int N=2e5+10;\nint a[N];\n\nint main(){\n    \/\/\u627e\u5230\u7b2c\u4e00\u4e2a\u5927\u4e8ex\u7684\u5143\u7d20\uff0c\u7b2c\u4e00\u4e2a\u5927\u4e8e\u7b49\u4e8ex\u7684\u5143\u7d20\n    \/\/\u6700\u540e\u4e00\u4e2a\u5c0f\u4e8ex\u7684\u5143\u7d20\uff0c\u6700\u540e\u4e00\u4e2a\u5c0f\u4e8e\u7b49\u4e8ex\u7684\u5143\u7d20\n    \/\/1 2 2 3 3 3 4 5 5 6 6 6 6 6 7\n    int n,q;\n    scanf("%d %d",&n,&q);\n    for(int i=1;i<=n;i++)\n        scanf("%d",&a[i]);\n    while(q--){\n        int x;\n        scanf("%d",&x);\n        int L=1,R=n,mid;\n        \/\/\u7b2c\u4e00\u4e2a\u5927\u4e8ex\u7684\u5143\u7d20\n        while(L<R){\n            int mid=L+R>>1;\n            if(a[mid]<=x)\n                L=mid+1;\n            else\n                R=mid;\n        }\n        printf("\u7b2c\u4e00\u4e2a\u5927\u4e8e%d\u7684\u5143\u7d20\u662fa[%d]=%d\\n",x,L,a[L]);\n        \/\/\u7b2c\u4e00\u4e2a\u5927\u4e8e\u7b49\u4e8ex\u7684\u5143\u7d20\n        L=1,R=n;\n        while(L<R){\n            int mid=L+R>>1;\n            if(a[mid]<x)\n                L=mid+1;\n            else\n                R=mid;\n        }\n        printf("\u7b2c\u4e00\u4e2a\u5927\u4e8e\u7b49\u4e8e%d\u7684\u5143\u7d20\u662fa[%d]=%d\\n",x,L,a[L]);\n        \/\/\u6700\u540e\u4e00\u4e2a\u5c0f\u4e8ex\u7684\u5143\u7d20\n        L=1,R=n;\n        while(L<R){\n            int mid=L+R+1>>1;\n            if(a[mid]>=x)\n                R=mid-1;\n            else\n                L=mid;\n        }\n        printf("\u6700\u540e\u4e00\u4e2a\u5c0f\u4e8e%d\u7684\u5143\u7d20\u662fa[%d]=%d\\n",x,L,a[L]);\n        \/\/\u6700\u540e\u4e00\u4e2a\u5c0f\u4e8e\u7b49\u4e8ex\u7684\u5143\u7d20\n        L=1,R=n;\n        while(L<R){\n            int mid=L+R+1>>1;\n            if(a[mid]>x)\n                R=mid-1;\n            else\n                L=mid;\n        }\n        printf("\u7b2c\u4e00\u4e2a\u5c0f\u4e8e\u7b49\u4e8e%d\u7684\u5143\u7d20\u662fa[%d]=%d\\n",x,L,a[L]);\n    }\n    return 0;\n}<\/code><\/pre>\n
      \u53e6\u5916\uff0cBV1d54y1q7k7\u4ecb\u7ecd\u7684\u53e6\u4e00\u79cd\u5199\u6cd5\u4e5f\u76f8\u5f53\u6709\u610f\u601d\uff0c\u8fc7\u51e0\u5929\u6709\u65f6\u95f4\u4e86\u6211\u4f1a\u7167\u7740\u6a21\u62df\u51e0\u904d\u7136\u540e\u5199\u51fa\u6765<\/p>\n","protected":false},"excerpt":{"rendered":"
      \uff08y\u603b\u592a\u5f3a\u529borz\uff09 \u6765\u770b\u4e00\u9053\u8fd9\u6837\u7684\u9898\uff1a \u7ed9\u51fa\u4e00\u4e2a\u5355\u8c03\u4e0d\u51cf\u6570\u5217\uff0c\u5bf9\u8fd9\u4e2a\u6570\u5217\u63d0\u51faq […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,13],"tags":[],"class_list":["post-294","post","type-post","status-publish","format-standard","hentry","category-9","category-13"],"_links":{"self":[{"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=\/wp\/v2\/posts\/294","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=294"}],"version-history":[{"count":1,"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=\/wp\/v2\/posts\/294\/revisions"}],"predecessor-version":[{"id":755,"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=\/wp\/v2\/posts\/294\/revisions\/755"}],"wp:attachment":[{"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=294"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=294"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.sssn.tech\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=294"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}