Vijos P1033 家族

~~~題目鏈接~~~

水果~

#include <cstdio>
#define N 5002
using namespace std;
int n = 0, m = 0, p = 0, father[N], rank[N];
int find(int x)
{
    if(father[x] != x)
        father[x] = find(father[x]);
    return father[x];
}

void Union(int x, int y)
{
    int fx = 0, fy = 0;
    fx = find(x);
    fy = find(y);
    if(fx == fy) return ;
    if(rank[fx]<rank[fy])
    {
        father[fx] = fy;
    }
    else
    {
        if(rank[fx] == rank[fy])
            rank[fx]++;
        father[fy] = fx;
    }
}

int main()
{
    int i = 0, x = 0, y = 0;
    scanf("%d %d %d", &n, &m, &p);
    for(i = 1; i<=n; i++)
    {
        rank[i] = 0;
        father[i] = i;
    }
    while(m--)
    {
        scanf("%d %d", &x, &y);
        Union(x, y);
    }
    while(p--)
    {
        scanf("%d %d", &x, &y);
        x = find(x);
        y = find(y);
        if(x == y) printf("Yes\n");
        else printf("No\n");
    }
    return 0;
}