杭电acm1213

并查集

for(i=0; i//注意要-1，因为这里的i是从0开始
uni(buf[i].x-1, buf[i].y-1);

#include 
#define N 1001

struct d{
	int x;
	int y;
}buf[N];

int parent[N];

int find(int x) {
	return x==parent[x] ? x : find(parent[x]);
}

void uni(int x, int y) {
	int a = find(x);
	int b = find(y);
	if(a==b)
		return ;
	parent[a] = b;
}

int main() {
	
	int t, n, m, i, ans;
	
	scanf("%d", &t);
	while(t--) {
		scanf("%d%d", &n, &m);
		for(i=0; i