{"id":323,"date":"2020-04-18T23:08:20","date_gmt":"2020-04-18T15:08:20","guid":{"rendered":"http:\/\/www.zyhcoding.club\/?p=323"},"modified":"2020-04-21T22:05:39","modified_gmt":"2020-04-21T14:05:39","slug":"%e6%9c%80%e5%b0%8f%e7%94%9f%e6%88%90%e6%a0%91%e5%8e%9f%e7%90%86","status":"publish","type":"post","link":"http:\/\/www.zyhcoding.club\/index.php\/2020\/04\/18\/%e6%9c%80%e5%b0%8f%e7%94%9f%e6%88%90%e6%a0%91%e5%8e%9f%e7%90%86\/","title":{"rendered":"\u6700\u5c0f\u751f\u6210\u6811\u539f\u7406"},"content":{"rendered":"

\u56fe\u7684\u6700\u5c0f\u751f\u6210\u6811<\/h2>\n

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\n\u5728\u5e26\u6743\u56fe\u7684\u6240\u6709\u751f\u6210\u6811\u4e2d\uff0c\u6743\u503c\u4e4b\u548c\u6700\u5c0f\u7684\u79f0\u4e3a\u6700\u5c0f\u751f\u6210\u6811<\/strong>\u3002
\n\u6700\u5c0f\u751f\u6210\u6811\u7684\u51e0\u4e2a\u6027\u8d28\uff1a<\/p>\n

\n

\u6700\u5c0f\u751f\u6210\u6811\u662f\u4e00\u4e2a\u8fde\u901a\u56fe
\n\u6700\u5c0f\u751f\u6210\u6811\u662f\u4e00\u68f5\u65e0\u73af\u6811\uff0c\u56e0\u6b64\u6709n-1\u6761\u8fb9\uff0c\u6811\u4e0a\u4efb\u610f\u4e24\u8282\u70b9\u4e4b\u95f4\u8def\u5f84\u552f\u4e00\u3002<\/p>\n<\/blockquote>\n

\u5e38\u7528\u7684\u751f\u6210\u6811\u7b97\u6cd5\u6709DFS\u751f\u6210\u6811\u3001BFS\u751f\u6210\u6811\u3001Prim \u6700\u5c0f\u751f\u6210\u6811\u548cKruskal\u6700\u5c0f\u751f\u6210\u6811\u7b97\u6cd5
\n\u6c42\u4e00\u4e2a\u56fe\u7684\u6700\u5c0f\u751f\u6210\u6811\u7684\u65b9\u6cd5\u6709\u4e24\u79cd\uff1aKruskal\u7b97\u6cd5\u548cPrim\u7b97\u6cd5\u3002<\/p>\n

Kruskal\u7b97\u6cd5<\/h4>\n

Krusakl\u7b97\u6cd5\u6c42\u6700\u5c0f\u751f\u6210\u6811\uff0c\u662f\u501f\u52a9\u4e8e\u5e76\u67e5\u96c6\u5b8c\u6210\u7684\u4e00\u4e2a\u6c42\u6700\u5c0f\u751f\u6210\u6811\u7b80\u5355\u6613\u5b9e\u73b0\u7684\u7b97\u6cd5\u3002
\n\u9996\u5148\u8981\u77e5\u9053\u51e0\u4e2a\u6027\u8d28\uff1a<\/p>\n

\n

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\n\u4e24\u4e2a\u8fde\u901a\u5757\u4e4b\u95f4\u7684\u6240\u6709\u8fb9\u4e2d\uff0c\u6743\u503c\u6700\u5c0f\u7684\u90a3\u6761\u8fb9\u4e00\u5b9a\u53c2\u4e0e\u6784\u6210\u6700\u5c0f\u751f\u6210\u6811\u3002<\/strong><\/p>\n<\/blockquote>\n

\u5728\u4e00\u4e2a\u5e26\u6743\u7684\u65e0\u5411\u8fde\u901a\u56fe\u4e2d\uff0c\u5148\u5bf9\u6240\u6709\u7684\u8fb9\u7684\u6743\u503c\u8fdb\u884c\u4ece\u5c0f\u5230\u5927\u6392\u5e8f\uff0c\u7136\u540e\uff0c\u904d\u5386\u8fd9\u4e9b\u8fb9\uff0c\u5982\u679c\u8fd9\u6761\u8fb9\u7684\u4e24\u4e2a\u7aef\u70b9\u5728\u540c\u4e00\u4e2a\u96c6\u5408\u5185\uff0c\u5373\u5728\u540c\u4e00\u4e2a\u8fde\u901a\u5757\u4e2d\uff0c\u90a3\u4e48\u8fd9\u6761\u8fb9\u5c31\u4e0d\u5728\u6700\u5c0f\u751f\u6210\u6811\u4e2d\uff1b\u5426\u5219\uff0c\u8fd9\u6761\u8fb9\u5728\u6700\u5c0f\u751f\u6210\u6811\u4e2d\uff0c\u7136\u540e\u5c06\u8fd9\u6761\u8fb9\u7684\u4e24\u4e2a\u70b9\u6240\u5728\u7684\u8fde\u901a\u5757\u5408\u5e76\uff0c\u5373\u5408\u5e76\u4e24\u4e2a\u96c6\u5408\u5373\u53ef\uff1b\u5f53\u5df2\u9009\u7684\u8fb9\u7684\u6570\u76ee\u4e3a\u603b\u7ed3\u70b9\u7684\u6570\u76ee-1(n-1)\u65f6\uff0c\u8bf4\u660e\u6700\u5c0f\u751f\u6210\u6811\u5df2\u7ecf\u6784\u6210\u3002<\/strong>\u524d\u4e24\u4e2a\u64cd\u4f5c\u6070\u597d\u5bf9\u5e94\u4e8e\u5e76\u67e5\u96c6\u7684\u67e5\u8be2\u4e24\u4e2a\u5143\u7d20\u662f\u5426\u5728\u540c\u4e00\u96c6\u5408\u5185\u548c\u5408\u5e76\u4e24\u4e2a\u96c6\u5408\uff0c\u6240\u4ee5\u7528\u5e76\u67e5\u96c6\u521a\u597d\u53ef\u4ee5\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u3002
\n\u6700\u5c0f\u751f\u6210\u6811\u6a21\u677f \u6d1b\u8c37P3366<\/a><\/p>\n

#include <algorithm>\n#include <iostream>\nusing namespace std;\nconst int maxn = 2e5+5;\ntypedef struct edge{\n    int u,v,w;\n}Edge;\nint n,m;\nint fa[5050];\nEdge e[maxn];\ninline bool cmp(Edge a,Edge b){\n    return a.w < b.w;\n}\ninline int find(int x){\n    while (x!=fa[x])    x = fa[x] = fa[fa[x]];\n    return x;\n}\nint main(){\n    std::ios::sync_with_stdio(false);\n    int ans,x,y,now;\n    cin >> n >> m;\n    for (int i=1;i<=m;i++)\n        cin >> e[i].u >> e[i].v >> e[i].w;\n    sort (e+1,e+m+1,cmp);          \/\/\u6309\u6743\u503c\u6392\u5e8f\n    ans = now = 0;\n    for (int i=1;i<=n;i++)  fa[i] = i;\n    for (int i=1;i<=m;i++){\n        x=find(e[i].u), y=find(e[i].v);\n        if (x==y)   continue;          \/\/\u4e24\u4e2a\u7ed3\u70b9\u5c5e\u4e8e\u540c\u4e00\u8fde\u901a\u5757\u65f6\n        ans += e[i].w;\n        fa[x] = y;\n        if (++now==n-1) break;\n    }\n    cout << ans;\n    return 0;\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
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