Submission #672649

#	Time	Username	Problem	Language	Result	Execution time	Memory
672649		Hanksburger	Beads and wires (APIO14_beads)	C++17	0 / 100	3 ms	4948 KiB

beads

#include <bits/stdc++.h>
#define ll long long
using namespace std;
vector<pair<ll, ll> > adj[200005];
pair<ll, ll> dfs(ll u, ll p, ll x)
{
    ll a[3]={0, (ll)1e18, (ll)1e18};
    for (ll i=0; i<adj[u].size(); i++)
    {
        ll v=adj[u][i].first, w=adj[u][i].second;
        if (v==p)
            continue;
        pair<ll, ll> r=dfs(v, u, w);
        a[2]=min(a[1]+r.first, a[2]+r.second);
        a[1]=min(a[0]+r.first, a[1]+r.second);
        a[0]+=r.second;
    }
    return {min(a[0], a[2]), min(min(a[0], a[2])+x, a[1])};
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    ll n, sum=0;
    cin >> n;
    for (ll i=1; i<n; i++)
    {
        ll u, v, w;
        cin >> u >> v >> w;
        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
        sum+=w;
    }
    cout << sum-dfs(1, 0, 0).first;
}

Compilation message (stderr)

beads.cpp: In function 'std::pair<long long int, long long int> dfs(long long int, long long int, long long int)':
beads.cpp:8:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 |     for (ll i=0; i<adj[u].size(); i++)
      |                  ~^~~~~~~~~~~~~~

• Subtask 1: 0 / 13
• Subtask 2: 0 / 15
• Subtask 3: 0 / 29
• Subtask 4: 0 / 43