并查集写成一个类

这个应该不用多说。。

#include <cstdio>
using namespace std;

const int maxn=10005;
int n, m;

struct Ufset{
    int fa[maxn], size[maxn];

    Ufset(int n){
        for (int i=1; i<=n; ++i){
            fa[i]=i;
            size[i]=1;
        }
        return;
    }

    int find(int x){
        int anc, realf;
        for (anc=x; fa[anc]!=anc; anc=fa[anc]);
        while (fa[x]!=x){
            realf=fa[x];
            fa[x]=anc;
            x=realf;
        }
        return anc;
    }

    bool in_same(int x, int y){
        if (find(x)!=find(y)) return false;
        else return true;
    }

    void merge_to(int x, int y){ //merge x to y
        int fx=find(x), fy=find(y);
        fa[fx]=fy;
        return;
    }

    void merge(int x, int y){
        if (size[x]>size[y])
            merge_to(y, x);
        else merge_to(x, y);
    }
};

int main(){
    scanf("%d%d", &n, &m);
    Ufset ufset1(n);
    int z, x, y;
    for (int i=0; i<m; ++i){
        scanf("%d%d%d", &z, &x, &y);
        if (z==1)
            ufset1.merge(x, y);
        else
            printf("%c
",
                   ufset1.in_same(x, y)?'Y':'N');
    }
    return 0;
}

来自luoguP3367