Submission #404139

#	Time	Username	Problem	Language	Result	Execution time	Memory
404139		opukittpceno_hhr	Beads and wires (APIO14_beads)	C++17	28 / 100	1090 ms	5836 KiB

beads

#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <string>
#include <cmath>
#include <cstdio>
#include <iomanip>
#include <fstream>
#include <cassert>
#include <cstring>
#include <unordered_set>
#include <unordered_map>
#include <numeric>
#include <ctime>
#include <bitset>
#include <complex>
#include <chrono>
#include <random>
#include <functional>

using namespace std;

#define int long long

const int INF = 1e18 + 239;
const int N = 2e5 + 7;

int to[N];
int dp[N][2];

vector<pair<int, int>> g[N];

void dfs(int cur, int p) {
    int S = 0;
    int mx = -INF;
    for (auto [t, w] : g[cur]) {
        if (t != p) {
            to[t] = w;
            dfs(t, cur);
            S += max(dp[t][0], dp[t][1]);
            mx = max(mx, dp[t][0] + to[t] - max(dp[t][0], dp[t][1]));
        }
    }
    dp[cur][1] = S + mx + to[cur];
    dp[cur][0] = S;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int n;
    cin >> n;
    for (int i = 0; i + 1 < n; i++) {
        int u, v, w;
        cin >> u >> v >> w;
        u--;
        v--;
        g[u].push_back({v, w});
        g[v].push_back({u, w});
    }
    int ans = 0;
    for (int i = 0; i < n; i++) {
        dfs(i, -1);
        ans = max(ans, dp[i][0]);
    }
    cout << ans << '\n';
}

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