【POJ】[1703]Find them, Catch them

#include<stdio.h>
int par[200200],rank[200200];
int find(int x) {
if(par[x]==x)
return x;
else
return par[x]=find(par[x]);
}
void unite(int x,int y) {
x=find(x);
y=find(y);
if(x==y)
return;
if(rank[x]<rank[y])
par[x]=y;
else {
par[y]=x;
if(rank[x]==rank[y])
rank[x]++;
}
}
int main() {
int T;
scanf("%d",&T);
while(T--) {
int n,m;
scanf("%d %d",&n,&m);
getchar();
for(int i=1; i<=2*n; i++) {
par[i]=i;
rank[i]=0;
}
while(m--) {
char c;
int x,y;
scanf("%c %d %d",&c,&x,&y);
getchar();
if(c=='D') {
unite(x,y+n);
unite(x+n,y);
} else if(c=='A') {
if(find(x)==find(y)||find(x+n)==find(y+n))
printf("In the same gang.\n");
else if(find(x)==find(y+n)||find(x+n)==find(y))
printf("In different gangs.\n");
else
printf("Not sure yet.\n");
}
}
}
return 0;
}