HDU 1879 继续畅通工程

来源：互联网发布：ubuntu kylin qq 编辑：程序博客网时间：2024/05/23 21:42

思想：最小生成树，Kruskal。

#include<stdio.h>#include<iostream>#include<algorithm>#include<math.h>#include<string.h>using namespace std;int per[105];int n;struct Edge{    int x;    int y;    int dis;}edge[5005];bool cmp(Edge a, Edge b){    return a.dis < b.dis;}void init(){    for(int i = 0; i <= n; i ++)        per[i] = i;}int find(int x){    if(x != per[x])        per[x] = find(per[x]);    return per[x];}void join(int x, int y){    int s = find(x);    int t = find(y);    if(s != t)    {        per[s] = t;    }}int kruskal(){    sort(edge+1,edge+n*(n-1)/2+1,cmp);    int sum = 0, count = 0;    for(int i = 1; i <= n*(n-1)/2; i++)    {        int s = find(edge[i].x);        int e = find(edge[i].y);        if(s != e)        {            join(s,e);            sum += edge[i].dis;            count ++;        }        if(count == n-1)            break;    }    return sum;}int main(){    while(scanf("%d",&n)!= EOF && n)    {        init();        int a, b, d, f;        for(int i = 1; i <= n*(n-1)/2; i ++)        {            scanf("%d%d%d%d",&a,&b,&d,&f);            edge[i].x = a;            edge[i].y = b;            if(f == 0)                edge[i].dis = d;            else if(f == 1)                edge[i].dis = 0;        }        int h = kruskal();        printf("%d\n",h);    }    return 0;}

如有错误，欢迎指出~

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