UVA - 11987 Almost Union-Find

题意:按要求操作集合

思路:并查集,因为我们一般都为i的祖先设为自己,但是当我们移动某个数字的时候,这个数字可能是这个集合的祖先,这会冲突,所以我们将i的祖先设为i+n

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int MAXN = 100010;

int n,m,fa[MAXN],sum[MAXN],num[MAXN];

void init(){
    for (int i = 1; i <= n; i++){
        fa[i] = i+n;
        fa[i+n] = i+n;
        sum[i+n] = i;
        num[i+n] = 1;
    }
}

int find(int x){
    if (x != fa[x])
        fa[x] = find(fa[x]);
    return fa[x];
}

int main(){
    int op,x,y;
    while (scanf("%d%d",&n,&m) != EOF){
        init();
        for (int i = 0; i < m; i++){
            scanf("%d",&op);
            if (op == 1){
                scanf("%d%d",&x,&y);
                int fx = find(x);
                int fy = find(y);
                if (fx != fy){
                    fa[fx] = fy;
                    sum[fy] += sum[fx];
                    num[fy] += num[fx];
                }
            }
            else if (op == 2){
                scanf("%d%d",&x,&y);
                int fx = find(x);
                int fy = find(y);
                if (fx != fy){
                    fa[x] = fy;
                    sum[fy] += x;
                    sum[fx] -= x;
                    num[fy]++;
                    num[fx]--;
                }
            }
            else {
                scanf("%d",&x);
                int fx = find(x);
                printf("%d %d\n",num[fx],sum[fx]);
            }
        }
    }
    return 0;
}



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