hdu 3172 Virtual Friends(并查集)

#include <cstdio>
#include <cstring>
#include <string>
#include <map>
#include <iostream>
#include <algorithm>

using namespace std;

const int maxn = 100005;

int N, M, far[maxn], cnt[maxn];
map<string, int> G;

inline void check(string s) {
if (G.count(s))
return;
cnt[M] = 1;
far[M] = M;
G[s] = M++;
}

int getfar(int x) {
return x == far[x] ? x : far[x] = getfar(far[x]);
}

void merge (int u, int v) {
int fu = getfar(u);
int fv = getfar(v);

if (fu != fv) {
far[fv] = fu;
cnt[fu] += cnt[fv];
}
cout << cnt[fu] << endl;
}

int main () {
int cas;
while (scanf("%d", &cas) == 1) {
while (cas--) {
M = 0;
G.clear();
char a[20], b[20];
scanf("%d", &N);

for (int i = 0; i < N; i++) {
scanf("%s%s", a, b);
check(a); check(b);
merge(G[a], G[b]);
}
}
}
return 0;
}