【NOI-2002】银河英雄传说

#include <bits/stdc++.h>
using namespace std;

const int N = 1 << 20;
int fa[N], dist[N], size[N];

int get(int x) {
    if (x == fa[x]) return x;
    int root = get(fa[x]);
    dist[x] += dist[fa[x]];
    return fa[x] = root;
}

void merge(int x,int y) {
    x = get(x), y = get(y);
    fa[x] = y, dist[x] += size[y];
    size[y] += size[x];
}

int main() {
    int  T; cin >> T;
    for (int i = 1; i <= 30000; ++i) {
        fa[i] =i; size[i] = 1;
    }
    while (T--) {
        char op; int x, y;
        getchar();
        scanf("%c %d %d",&op, &x, &y);
        if (op == 'M') {
            merge(x,y);
        }
        if (op == 'C') {
            if (get(x) == get(y)) {
                printf("%d\n",abs(dist[x]-dist[y])-1);
            }  else  {
                puts("-1");
            }
        }
    }
    return 0;
}