Submission #1120333

#	Time	Username	Problem	Language	Result	Execution time	Memory
1120333		matei__b	Duathlon (APIO18_duathlon)	C++17	0 / 100	1103 ms	1048576 KiB

count_triplets

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp> 
#include <ext/pb_ds/tree_policy.hpp> 
#define ll long long
#define ull unsigned long long
#define ld long double
#define chad char
#define mod 666'013
#define dim 100005
#define lim 1000000
#define BASE 31
#define NMAX 21'005
#define FOR(i,a,b) for(int i=(a); i<=(b); i++)
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update> 
#define pii pair<int,int>
#define pb push_back
#define mp make_pair
#define nr_biti __builtin_popcount
using namespace __gnu_pbds; 
using namespace std;

ifstream fin("b.in");
ofstream fout("b.out");

int t=1;
ll n,m;
vector<int> g[dim];
ll ans;
ll sz[dim];
bool viz[dim];

void dfs(int nod,int daddy=0)
{
    sz[nod]=1;
    viz[nod]=1;
    for(auto it:g[nod])
    {
        if(it==daddy)
            continue; 

        dfs(it,nod);
        sz[nod]+=sz[it];
    }

    ans+=(2LL*(sz[nod]-1)*(n-sz[nod]));
    for(auto it:g[nod])
    {
        if(it==daddy)
            continue;

        ans+=(sz[it]*(sz[nod]-1-sz[it]));
    }
}

void solve()
{
    cin >> n >> m;
    for(int i=1; i<=m; i++)
    {
        int x,y;
        cin >> x >> y;
        g[x].pb(y);
        g[y].pb(x);
    }

    for(int i=1; i<=n; i++)
    {
        if(!viz[i])
            dfs(i);
    }
    cout << ans;
}   

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    //cin >> t;
    while(t--)
        solve();

    return 0;
}

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