Submission #1127195

#	Time	Username	Problem	Language	Result	Execution time	Memory
1127195		czauderna	Duathlon (APIO18_duathlon)	C++20	23 / 100	1128 ms	1114112 KiB

count_triplets

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
typedef long long ll;
const int N = 1e5+3;
vector<int> grf[N], tree[N];
int pre[N], low[N], cnt;
ll siz[N], out, ile;
bool odw[N];
void dfs(int v, int p){
	odw[v]=1;
	ile++;
	for(auto w:grf[v]){
		if(w==p) continue;
		dfs(w, v);
		siz[v]+=siz[w];
	}
	siz[v]++;
}
void dfs2(int v, int p){
	for(auto w:grf[v]){
		if(w==p) continue;
		dfs2(w, v);
	}
	if(v!=p) out-=(siz[v]*(siz[v]-1) + (ile-siz[v])*(ile-siz[v]-1));
}
int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int n, m;
	cin >> n >> m;
	for(int i=0; i<m; i++){
		int a, b;
		cin >> a >> b;
		grf[a].pb(b);
		grf[b].pb(a);
	}
	for(int i=1; i<=n; i++){
		if(odw[i]) continue;
		ile=0;
		dfs(i, i);
		dfs2(i, i);
		out+=ile*(ile-1)*(ile-2);
	}
	cout << out << '\n';
	return 0;
}

• 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