Submission #916287

#	Time	Username	Problem	Language	Result	Execution time	Memory
916287		Alcabel	Beads and wires (APIO14_beads)	C++17	28 / 100	1043 ms	6492 KiB

beads

#include <bits/stdc++.h>
using namespace std;

const int maxn = 2e5;
const long long inf = 1e11;
vector<pair<int, int>> g[maxn];
long long dp[maxn][2];

void dfsCalc(int v, int p) {
    dp[v][0] = 0, dp[v][1] = -inf;
    for (const auto& [u, w] : g[v]) {
        if (u != p) {
            dfsCalc(u, v);
            dp[v][0] += max(dp[u][0], dp[u][1] + w);
        }
    }
    for (const auto& [u, w] : g[v]) {
        if (u != p) {
            dp[v][1] = max(dp[v][1], dp[v][0] - max(dp[u][0], dp[u][1] + w) + dp[u][0] + w);
        }
    }
}

void solve() {
    int n;
    cin >> n;
    for (int i = 0; i < n - 1; ++i) {
        int v, u, w;
        cin >> v >> u >> w;
        --v, --u;
        g[v].emplace_back(u, w);
        g[u].emplace_back(v, w);
    }
    long long ans = 0;
    for (int r = 0; r < n; ++r) {
        dfsCalc(r, -1);
        ans = max(ans, dp[r][0]);
    }
    cout << ans << '\n';
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    int T = 1;
    cin >> T;
    while (T--) {
        solve();
        cerr << "-----------\n";
        cout << "-----------\n";
    }
#else
    int T = 1;
    // cin >> T;
    while (T--) {
        solve();
    }
#endif

    return 0;
}

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