{"id":292,"date":"2022-07-30T18:47:10","date_gmt":"2022-07-30T10:47:10","guid":{"rendered":"https:\/\/blog.cirno.fun\/?p=292"},"modified":"2024-09-12T09:36:31","modified_gmt":"2024-09-12T01:36:31","slug":"%e5%bd%92%e5%b9%b6%e6%8e%92%e5%ba%8f","status":"publish","type":"post","link":"https:\/\/blog.sssn.tech\/?p=292","title":{"rendered":"\u5f52\u5e76\u6392\u5e8f"},"content":{"rendered":"

\"file\"<\/p>\n

\u5f52\u5e76\u6392\u5e8f\u662f\u4e00\u79cd\u65f6\u95f4\u590d\u6742\u5ea6\u4e3aO(NlogN)<\/code>\u7684\u6392\u5e8f\u7b97\u6cd5\uff0c\u5176\u548c\u5feb\u901f\u6392\u5e8f\u4e00\u6837\u57fa\u4e8e\u5206\u6cbb\u7684\u601d\u60f3\uff0c\u4f46\u53c8\u4e0d\u5b8c\u5168\u76f8\u540c\u3002\u6bd4\u8d77\u5feb\u901f\u6392\u5e8f\u5e73\u5747O(NlogN)<\/code>\u7684\u590d\u6742\u5ea6(\u6700\u5dee\u9000\u5316\u6210N^2<\/code>),\u5f52\u5e76\u6392\u5e8f\u4e0d\u4f1a\u9000\u5316\uff0c\u662f\u4e00\u79cd\u7a33\u5b9a\u7684\u7b97\u6cd5<\/p>\n

\u5bf9\u4e8e\u65e0\u5e8f\u6570\u5217a[N]<\/code>\u5728\u95ed\u533a\u95f4[L,R]<\/code>\u7684\u5f52\u5e76\u6392\u5e8f:<\/p>\n

    \n
  1. \u627e\u51fa\u6570\u5217\u4e2d\u70b9mid<\/li>\n
  2. \u9012\u5f52\u8bbf\u95ee\u7531\u4e2d\u70b9\u95f4\u65ad\u5f00\u7684\u4e24\u4e2a\u5b50\u5e8f\u5217<\/li>\n
  3. \u5c06\u4e24\u4e2a\u6392\u5e8f\u597d\u7684\u5b50\u5e8f\u5217\u586b\u5165[L,R]<\/code><\/li>\n<\/ol>\n

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    \u73b0\u5728\u89e3\u51b3\u5c06\u4e24\u4e2a\u6709\u5e8f\u6570\u5217\u5408\u5e76\u6210\u4e00\u4e2a\u7684\u95ee\u9898\uff0c\u6211\u4eec\u7528\u53cc\u6307\u9488\u6cd5\uff0c\u4f9d\u6b21\u4ece\u5934\u8bbf\u95ee\u4e24\u4e2a\u6570\u5217\uff0c\u6bd4\u8f83\u4e24\u4e2a\u5143\u7d20\u7684\u5927\u5c0f\uff0c\u586b\u5165\u5c0f\u7684\u4e00\u4e2a\uff0c\u76f4\u5230\u4e00\u4e2a\u6307\u9488\u6307\u5411\u5176\u6570\u5217\u7684\u672b\u5c3e\uff0c\u6211\u4eec\u5c31\u5c06\u53e6\u4e00\u6570\u5217\u7684\u5269\u4f59\u5143\u7d20\u5168\u90e8\u586b\u5165<\/p>\n

    \u5b8c\u6574\u4ee3\u7801\u5982\u4e0b<\/p>\n

    void merge_sort(int a[],int l,int r){\n    if(l>=r)\n        return ;\n    int mid=(l+r)\/2;\n\n    merge_sort(a,l,mid);\n    merge_sort(a,mid+1,r);\n\n    \/\/\u4e24\u4e2a\u5b50\u5e8f\u5217\u5206\u522b\u662fl~mid\uff0cmid+1~r\n    int t=0,i=l,j=mid+1;\/\/t\u7528\u6765\u5f80temp\u4e2d\u88c5\u586b\uff0ci\uff0cj\u662f\u4e24\u4e2a\u6307\u9488\n    while(i<=mid && j<=r)\/\/\u6709\u4e00\u4e2a\u6307\u9488\u5230\u5934\u5c31\u505c\u6b62\n        if(a[i]<=a[j])\n            temp[++t]=a[i++];\n        else\n            temp[++t]=a[j++];\n    \/\/\u522b\u5fd8\u4e86\u628a\u6ca1\u6709\u5230\u5934\u7684\u5b50\u5e8f\u5217\u5269\u4f59\u5143\u7d20\u5168\u90e8\u88c5\u586b\u8fdbtemp\n    while(i<=mid)    temp[++t]=a[i++];\n    while(j<=r)  temp[++t]=a[j++];\n\n    \/\/\u5c06temp\u4e2d\u6392\u5e8f\u597d\u7684\u5143\u7d20\u4f9d\u6b21\u88c5\u5165a[]\n    for(int i=l,j=1;i<=r;i++,j++)\n        a[i]=temp[j];\n}\n<\/code><\/pre>\n
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