【LibreOJ109】【模板】并查集

并查集模板，就酱紫。

#include<iostream>
using namespace std;
#define mod 998244353

long long ans;

int fa[4000010];
int find(int x){ return fa[x]==x?x:fa[x]=find(fa[x]);}
void merge(int x,int y){x=find(x),y=find(y); if(x!=y)fa[x]=y;}

int main(){
    ios::sync_with_stdio(false);
    int n, m;
    cin>>n>>m;
    for(int i = 1; i <= n; i++)fa[i] = i;
    for(int i = 1; i <= m; i++){
        int op, u, v;
        cin>>op>>u>>v;
        if(op==0){
            merge(u,v);
        }else{
            if(find(u)==find(v))ans = (ans*2+1)%mod;
            else ans = (ans*2)%mod;
        }
    }
    cout<<ans<<"
";
    return 0;
}