Submission #772000

#	Time	Username	Problem	Language	Result	Execution time	Memory
772000		CyberCow	Duathlon (APIO18_duathlon)	C++17	23 / 100	1082 ms	1048576 KiB

count_triplets

//#include <bits/stdc++.h>
#include <random>
#include <algorithm>
#include <bitset>
#include <chrono>
#include <cmath>
#include <deque>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include <chrono>
#define fr first
#define sc second
#define ad push_back
using namespace std;
using ll = long long;
mt19937 rnd(348502);
const int N = 300005;
vector<ll> v[N];
ll sz[N];
ll color[N];
ll guyn = 0;
ll chap;
 
void Dfs(ll g)
{
    sz[g] = 1;
    color[g] = guyn;
    for (auto to : v[g])
    {
        if (color[to] == 0)
        {
            Dfs(to);
            sz[g] += sz[to];
        }
    }
}
 
ll koxqan = 0;
 
void Dfs1(ll g, ll guyn, int p)
{
    koxqan += sz[g] * (chap - sz[g]);
    for (auto to : v[g])
    {
        if (color[to] == guyn && to != p)
        {
            Dfs1(to, guyn, g);
        }
    }
}
 
void solve()
{
    ll n, i, j, x, y, m;
    cin >> n >> m;
    vector<pair<ll, ll>> kox;
    for ( i = 0; i < m; i++)
    {
        cin >> x >> y;
        kox.push_back({ x, y });
        v[x].push_back(y);
        v[y].push_back(x);
    }
    ll ans = 0;
    for ( i = 1; i <= n; i++)
    {
        if (color[i] == 0)
        {
            koxqan = 0;
            guyn++;
            Dfs(i);
            chap = sz[i];
            Dfs1(i, guyn, -1);
            ans += koxqan - (chap * (chap - 1) / 2);
        }
    }
    cout << ans * 2;
}
 
 
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    ll tt = 1;
    //cin >> tt;
    while (tt--) {
        solve();
    }
    return 0;
}

Compilation message (stderr)

count_triplets.cpp: In function 'void solve()':
count_triplets.cpp:64:14: warning: unused variable 'j' [-Wunused-variable]
   64 |     ll n, i, j, x, y, m;
      |              ^

• 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