poj 1703 Find them, Catch them（并查集）

1
5 5
A 1 2
D 1 2
A 1 2
D 2 4
A 1 4

Not sure yet.
In different gangs.
In the same gang.

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<queue>
#include<vector>

#define L(x) (x<<1)
#define R(x) (x<<1|1)
#define MID(x,y) ((x+y)>>1)
using namespace std;
#define N 100005

int father
,num
;
int n,m;

int cha(int x)
{
	if(x!=father[x])
	{
		int t=father[x];
		father[x]=cha(father[x]);
		num[x]=(num[x]+num[t])%2; //递归，更新父亲节点，在更新这个节点
	}
	return father[x];
}

int main()
{
	int t,i,j;
	scanf("%d",&t);
	while(t--)
	{
		scanf("%d%d",&n,&m);
		for(i=0;i<=n;i++)
		{
			father[i]=i;
			num[i]=0;
		}
		char c[10];

		int x,y;
		while(m--)
		{
			scanf("%s%d%d",c,&x,&y);

			if(c[0]=='D')
			{
				int xx=cha(x);
				int yy=cha(y);
				father[xx]=yy;
				num[xx]=(-num[x]+num[y]+1+2)%2;
			}
			else
			{
				int xx=cha(x);
				int yy=cha(y);
				if(xx==yy)  //可以确定这两个点有关系
				{
					if(num[x]==num[y])
						printf("In the same gang.\n");
					else
						printf("In different gangs.\n");
				}
				else
					printf("Not sure yet.\n");
			}
		}
	}
	return 0;
}