Submission #73705178

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Source Code Expand

#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using ll = long long;
#define rep(i, n) for(int  i = 0; i < (n); ++i)
template<typename T> bool chmin(T& a, T b){if(a > b){a = b; return true;} return false;}
template<typename T> bool chmax(T& a, T b){if(a < b){a = b; return true;} return false;}
const long long INF = 1LL << 60;
using Graph = vector<vector<int>>;
int gcd(int a, int b){
    if(b == 0) return a;  
    else return gcd(b, a%b);
}
struct Compare {
    bool operator()(const pair<ll, int>& a, const pair<ll, int>& b) {
        return a.first > b.first;  
    }
};
using namespace atcoder;
using mint = modint998244353;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n,m; cin >> n >> m;
    dsu d(n);
    vector<pair<int,int>> edge;
    rep(i,m){
        int u,v; cin >> u >> v;
        u--; v--;
        edge.push_back({u,v});
    }
    int co = n;
    map<int, mint> mp;
    mint now = 2;
    for(int i=1;i<=m;i++){
        mp[i] = now;
        now *= 2;
    }
    mint ans = 0;
    for(int i=m;i>0;i--){
        auto [u,v] = edge[i-1];
        if(d.same(u,v)) continue;
        if(co == 2){
            ans += mp[i];
        }else{
            d.merge(u, v);
            co--;
        }
    }
    cout << ans.val() << endl;
}

Submission Info

Judge Result