poj1703 并查集

#include <iostream>
using namespace std;
int f[200001],n,m,x,y,cas;
char c;
int find(int x) {
if (x!=f[x]) f[x] = find(f[x]);
return f[x];
}
void Union(int x,int y) {
int px = find(x);
int py = find(y);
if (px != py) f[px] = py;
}
int main() {
scanf("%d",&cas);
while (cas--) {
scanf("%d%d",&n,&m);
for (int i=1;i<=2*n;i++) f[i] = i;
for (int i=1;i<=m;i++) {
scanf("%c%c %d %d",&c,&c,&x,&y);
if (c=='D') {
Union(x,y+n);
Union(y,x+n);
}
else {
if (find(x)==find(y)) printf("In the same gang.\n");
else if (find(x)==find(y+n)||find(y)==find(x+n))
printf("In different gangs.\n");
else printf("Not sure yet.\n");
}
}
}
return 0;
}