Find them, Catch them（poj 1703）

#include<cstdio>
#include<iostream>
#include<cstring>
#define M 100010
using namespace std;
int fa[M*2];
int find(int x)
{
    if(fa[x]==x)return x;
    return fa[x]=find(fa[x]);
}
void init()
{
    int n,m;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=2*n;i++)
      fa[i]=i;
    for(int i=1;i<=m;i++)
    {
        char c;
        int x,y;
        cin>>c;
        scanf("%d%d",&x,&y);
        int a=find(x),b=find(y);
        int aa=find(x+n),bb=find(y+n);
        if(c==‘A‘)
        {
            if(a==b)printf("In the same gang.\n");
            else if(a==bb||b==aa)printf("In different gangs.\n");
            else printf("Not sure yet.\n");
        }
        else
        {
            fa[aa]=b;
            fa[bb]=a;
        }
    }
}
int main()
{
    int T;
    scanf("%d",&T);
    while(T--)
    {
        memset(fa,0,sizeof(fa));
        init();
    }
    return 0;
}