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Submission #754004

# Submission time Handle Problem Language Result Execution time Memory
754004 2023-06-06T13:17:19 Z thinknoexit Beads and wires (APIO14_beads) C++17
0 / 100
 3 ms 5028 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 200200;
vector<pair<int, ll>> adj[N];
ll dp[2][N];
void dfs(int v, int p = 0) {
    if (adj[v].size() == 1 && adj[v][0].first == p) {
        dp[0][v] = 0;
        dp[1][v] = -4e9;
    }
    ll mx = -4e9, mx2 = -4e9;
    ll sum = 0;
    for (auto& [x, w] : adj[v]) {
        if (x == p) continue;
        dfs(x, v);
        ll val = max(dp[0][x], dp[1][x] + w);
        sum += val;
        ll val2 = dp[0][x] + w - val;
        if (val2 > mx) {
            mx2 = mx;
            mx = val2;
        }
        else if (val2 > mx2) {
            mx2 = val2;
        }
    }
    dp[1][v] = sum + mx;
    dp[0][v] = max(sum, sum + mx + mx2);
}
int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    // freopen("stdin", "r", stdin);
    // freopen("stdout", "w", stdout);
    int n;
    cin >> n;
    for (int i = 1;i < n;i++) {
        int u, v;
        ll w;
        cin >> u >> v >> w;
        adj[u].push_back({ v,w });
        adj[v].push_back({ u,w });
    }
    dfs(1);
    cout << max(0ll, dp[0][1]);
    return 0;
}
/*
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 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 3 ms 5028 KB Output is correct
6 Incorrect 3 ms 4948 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #2
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 3 ms 5028 KB Output is correct
6 Incorrect 3 ms 4948 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 3 ms 5028 KB Output is correct
6 Incorrect 3 ms 4948 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 3 ms 5028 KB Output is correct
6 Incorrect 3 ms 4948 KB Output isn't correct
7 Halted 0 ms 0 KB -