Find them, Catch them---poj1703（并查集）

#include <iostream>
#include <cstdio>
#include <cstring>
#include <stdlib.h>
#include <math.h>
#include <queue>
#include <algorithm>
using namespace std;

const int oo = 0x3f3f3f3f;
const int N = 100050;

int f
, r
;///r[i]代表f[i]与i的关系，1代表不同类，0代表同类；

int Find(int x)
{
int k=f[x];
if(x!=f[x])
{
f[x] = Find(f[x]);
r[x] = (r[x]+r[k])%2;
}
return f[x];
}

int main()
{
int t;
scanf("%d", &t);

while(t--)
{
char s[10];
int n, m, i, a, b, fa, fb;

scanf("%d%d", &n, &m);

for(i=0; i<=n; i++)
{
f[i] = i;
r[i] = 0;
}

for(i=1; i<=m; i++)
{
scanf("%s%d%d", s, &a, &b);

if(s[0]=='A')
{

fa = Find(a);
fb = Find(b);

if(fa!=fb)
printf("Not sure yet.\n");
else
{
if(r[a]==r[b])
printf("In the same gang.\n");
else
printf("In different gangs.\n");
}

}
else
{
fa = Find(a);
fb = Find(b);

if(fa!=fb)
{
f[fa] = fb;
r[fa] = (r[b] - r[a] + 1 + 2)%2;
}
}
}
}
return 0;
}