poj1703--Find them, Catch them

#include <set>
#include <map>
#include <cmath>
#include <ctime>
#include <queue>
#include <stack>
#include <cctype>
#include <cstdio>
#include <string>
#include <vector>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
typedef unsigned long long ull;
typedef long long ll;
const int inf = 0x3f3f3f3f;
const double eps = 1e-8;
const int maxn =1e5+10;
int n,m;
int  pa[maxn],oet[maxn];
void init()
{
    for (int i = 0; i < maxn; i++)
    {
        pa[i] = i;
    }
    memset(oet,0,sizeof(oet));
}
int find(int x)
{
    if (pa[x] == x)
    {
        return x;
    }
    else
    {
        int tmp = pa[x];
        pa[x] = find(tmp);
        oet[x] = (oet[x]+oet[tmp])%2;
        return pa[x];
    }
}
void union_set(int x,int y,int d)
{
    int fx = find(x);
    int fy = find(y);
    if (fx == fy)
        return;
    pa[fx] = fy;
    oet[fx] = (oet[y]-oet[x]+d+2)%2;//oet[x] 表示x对其父亲的偏移量。至于这个式子怎么退出的，，就用向量来推，起点到终点
}
void query(int x,int y)
{
    int fa = find(x);
    int fy = find(y);
    if (fa != fy)                       //x y不在一个集合中自然不能确定关系。
    {
         printf("Not sure yet.\n");
         return;
    }
    int tmp = (oet[x]-oet[y]+2)%2;       //在求这种关系式的时候可以借助数学的向量来推导。
    if (tmp==1)
        printf("In different gangs.\n");
    else
        printf("In the same gang.\n");
}
int main(void)
{
    int t;
    cin>>t;
    while (t--)
    {
        scanf("%d%d",&n,&m);
        char ch[10];
        int x,y;
        init();
        for (int i = 0; i < m; i++)
        {
            scanf("%s%d%d",ch,&x,&y);
            if (ch[0]==‘A‘)
            {
                query(x,y);
            }
            else
            {
                union_set(x,y,1);
            }
        }
    }
    return 0;
}