poj 1926 Pollution 并查集解决污染计算问题

#include <cstdio>
#define N 101
int f[N];
double p[N];//记录顶点污染指数
int con[N];  //记录连通数
int rank[N]; 
int total[N];//记录该集合总的连通数量
int Find(int x)
{
	if(x != f[x])
	{
		f[x] = Find(f[x]);
	}
	return f[x];
}
void connect(int x, int y)
{
	x = Find(x);
	y = Find(y);
	if(x == y)
		return;

	if(rank[x] > rank [y])
	{
		f[y] = x;
		p[x] = p[y] + p[x];
		total[x] = total[x] + total[y];
	}
	else
	{
		f[x] = y;
		if(rank[x] == rank[y])
			 rank[y]++;
		p[y] = p[x] + p[y];
		total[y] = total[x] + total[y];
	}
}
int main()
{
	int t, n, m;
	int x, y;
	scanf("%d", &t);
	while(t)
	{
		scanf("%d %d", &n, &m);
		for(int i = 1; i <= n ; i++)
		{
			scanf("%lf", &p[i]);
			con[i] = 0;
			rank[i] = 0;
			f[i] = i;
			total[i] = 0;
		}
		for(int i = 1; i <= m; i++)
		{
			scanf("%d %d", &x, &y);
			con[x]++;
			con[y]++;
			total[Find(x)]++;
			total[Find(y)]++;
			connect(x, y);
		}
		for(int i = 1; i <= n; i++)
		{
			x = Find(i);
			if(con[i] == 0)
				printf("%.3f\n",p[i]);
			else
				printf("%.3f\n",p[x] * con[i] / total[x]);
		}
		printf("\n");
		t--;
	}
	return 0;
}