Submission #980785

#	Time	Username	Problem	Language	Result	Execution time	Memory
980785		Unforgettablepl	Duathlon (APIO18_duathlon)	C++17	23 / 100	1083 ms	1048576 KiB

count_triplets

#include <bits/stdc++.h>
using namespace std;

#define int long long

vector<int> adj[200001];
bool visited[200001];
int subsize[200001];
int ans,full;

int dfs(int x,int p,int depth){
    ans+=depth;
    subsize[x]=1;
    visited[x]=true;
    for(int&i:adj[x])if(i!=p)subsize[x]+=dfs(i,x,depth+1);
    return subsize[x];
}

int reroot(int x,int p,int currans){
    int tot = currans;
    for(int&i:adj[x])if(i!=p)tot+=reroot(i,x,currans+full-2*subsize[i]);
    return tot;
}

int32_t main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int n,m;
    cin >> n >> m;
    for(int i=1;i<=m;i++){
        int a,b;cin>>a>>b;
        adj[a].emplace_back(b);
        adj[b].emplace_back(a);
    }
    int myans = 0;
    for(int i=1;i<=n;i++)if(!visited[i]){
        ans = 0;
        full = dfs(i,0,-1);
        myans+=reroot(i,0,ans);
    }
    cout << myans+n << '\n';
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 8
• Subtask 4: 10 / 10
• Subtask 5: 13 / 13
• Subtask 6: 0 / 15
• Subtask 7: 0 / 20
• Subtask 8: 0 / 8
• Subtask 9: 0 / 10