九度OJ 1028 继续畅通工程

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#include <stdio.h>
#include <algorithm>
using namespace std;

int Tree[100];
int findRoot(int x)
{
	if(Tree[x] == -1) return x;
	else{
		int tmp = findRoot(Tree[x]);
		Tree[x] = tmp;
		return tmp;
	}
}

struct Edge{
	int a , b;
	int cost;
	int status;
	bool operator < (const Edge &A) const {
		return cost < A.cost;
	}
}edge[5000];

int main()
{
	int n;
	while(scanf("%d",&n) != EOF && n != 0){
		for(int i = 0 ; i  < n * (n-1) / 2 ; ++i){
			scanf("%d%d%d%d",&edge[i].a,&edge[i].b,&edge[i].cost,&edge[i].status);
			if(edge[i].status == 1){		//与1024不同的地方，道路已修时，边的权值赋为0
				edge[i].cost = 0;
			}
		}
		sort(edge , edge + n * (n-1) / 2);

		for(int i = 1 ; i <= n ; ++i){
			Tree[i] = -1;
		}

		int ans = 0;
		for(int i = 0 ; i < n * (n-1) / 2 ; ++i){
			int a , b;
			a = findRoot(edge[i].a);
			b = findRoot(edge[i].b);
			if(a != b){
				Tree[a] = b;
				ans += edge[i].cost;
			}
		}
		printf("%d\n",ans);
	}
	return 0;
}