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Submission #964506

# Submission time Handle Problem Language Result Execution time Memory
964506 2024-04-17T03:44:47 Z 12345678 Beads and wires (APIO14_beads) C++17
0 / 100
 2 ms 6748 KB 
#include <bits/stdc++.h>

using namespace std;

const int nx=2e5+5;

#define ll long long

ll n, u, v, w, dp[2][nx];
vector<pair<ll, ll>> d[nx];

void dfs(int u, int p, ll pw)
{
    vector<ll> df;
    for (auto [v, w]:d[u]) if (v!=p) dfs(v, u, w), dp[0][u]+=dp[1][v], df.push_back(w+dp[0][v]-dp[1][v]);
    sort(df.begin(), df.end());
    reverse(df.begin(), df.end());
    if (w!=-1&&df.size()>=1) dp[1][u]=max(dp[0][u], dp[0][u]+df[0]+pw);
    if (df.size()>=2) dp[0][u]=max(dp[0][u], dp[0][u]+df[0]+df[1]);
    dp[1][u]=max(dp[1][u], dp[0][u]);
    //cout<<"debug "<<u<<' '<<dp[0][u]<<' '<<dp[1][u]<<'\n';
}

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n;
    for (int i=1; i<n; i++) cin>>u>>v>>w, d[u].push_back({v, w}), d[v].push_back({u, w});
    dfs(1, 1, -1);
    cout<<dp[0][1];
}
/*
10
4 10 2
1 2 21
1 3 13
6 7 1
7 9 5
2 4 3
2 5 8
1 6 55
6 8 34
*/

Subtask #1
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 6748 KB Output is correct
2 Correct 1 ms 6748 KB Output is correct
3 Correct 1 ms 6748 KB Output is correct
4 Correct 2 ms 6744 KB Output is correct
5 Correct 2 ms 6748 KB Output is correct
6 Incorrect 1 ms 6748 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #2
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 6748 KB Output is correct
2 Correct 1 ms 6748 KB Output is correct
3 Correct 1 ms 6748 KB Output is correct
4 Correct 2 ms 6744 KB Output is correct
5 Correct 2 ms 6748 KB Output is correct
6 Incorrect 1 ms 6748 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 6748 KB Output is correct
2 Correct 1 ms 6748 KB Output is correct
3 Correct 1 ms 6748 KB Output is correct
4 Correct 2 ms 6744 KB Output is correct
5 Correct 2 ms 6748 KB Output is correct
6 Incorrect 1 ms 6748 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 6748 KB Output is correct
2 Correct 1 ms 6748 KB Output is correct
3 Correct 1 ms 6748 KB Output is correct
4 Correct 2 ms 6744 KB Output is correct
5 Correct 2 ms 6748 KB Output is correct
6 Incorrect 1 ms 6748 KB Output isn't correct
7 Halted 0 ms 0 KB -