제출 #1343180

#제출 시각아이디문제언어결과실행 시간메모리
1343180vjudge1철인 이종 경기 (APIO18_duathlon)C++20
100 / 100
212 ms62680 KiB
#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N =500100;
vector<int> adj[N],adj2[N];
int vis[N],SZ,CC,soc,id[N],dep[N],in[N],low[N],par[N],sz[N],CC2,par2[N],res;
set<pair<int,int>> cycs[N];
int abp(int n){
    return par2[n]?par2[n]=abp(par2[n]):n;
}
void merge(int a,int b){
    a=abp(a),b=abp(b);
    if(a-b)par2[a]=b;
}
void dfs1(int n,int p){
    SZ++;
    dep[n]=dep[p]+1;
    low[n]=id[n]=++CC;
    for(auto x:adj[n]){
        if(x==p)continue;
        if(!id[x]){
            dfs1(x,n);
            low[n]=min(low[n],low[x]);
            if(low[x]>id[n])
                adj2[n].push_back(x);
        }else if(dep[x]<dep[n])
            cycs[n].insert({dep[x],++CC}),low[n]=min(low[n],low[x]);
    }
}
void dfs2(int n){
    for(auto x:adj[n]){
        if(dep[x]!=dep[n]+1)
            continue;
        dfs2(x);
        if(cycs[x].size()&&cycs[x].begin()->first<dep[n]){
            if(cycs[n].size()) merge(cycs[x].begin()
                        ->second,cycs[n].begin()->second);
            cycs[n].insert(*cycs[x].begin());
        }
    }
    if(cycs[n].size())
        in[n]=cycs[n].begin()->second;
}
void dfs3(int n,int p){
    for(auto x:adj[n])
        if(dep[x]==dep[n]+1)
            dfs3(x,n);
    adj2[abp(in[n])].push_back(n);
    if(abp(in[n])-abp(in[par[n]]))
        par[abp(in[n])]=p;
}
void dfs4(int n){
    int sum=0,x;
    for(auto i:adj2[n]){
        dfs4(i);
        sum+=sz[n]*sz[i];
        sz[n]+=sz[i];
    }
    x=sz[n];
    sz[n]+=n<=soc;
    sum+=(SZ-sz[n])*x;
    res+=(n>soc?adj2[n].size()-1:1)*sum*2;
}
signed main(){
    cin.tie(0)->sync_with_stdio(0);
    int n,m;
    cin>>n>>m;
    soc=CC=n;
    for(int i=0;i<m;i++){
        int a,b;
        cin>>a>>b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    for(int i=1;i<=n;i++)if(!id[i]){
        SZ=0;
        int prv=CC;
        dfs1(i,0);
        dfs2(i);
        dfs3(i,0);
        for(int j=prv+1;j<=CC;j++)
            if(!par2[j])
                adj2[par[j]].push_back(j);
        dfs4(i);
    }
    cout<<res<<'\n';
}
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...