Submission #1222557

#	Time	Username	Problem	Language	Result	Execution time	Memory
1222557		nguyenvanhieu812009	Sjekira (COCI20_sjekira)	C++20	10 / 110	264 ms	589824 KiB

sjekira

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

const long long maxn = 1e5 + 1;

struct cmp {
    long long idx;
    long long value;
};

bool sapxep(cmp a, cmp b) {
    return a.value > b.value;
}

long long n;
cmp t[maxn];
vector<long long> adj[maxn];
long long values[maxn]; // để truy cập giá trị nhanh qua chỉ số

void dfs(long long u, long long &ans, vector<bool> &visited) {
    visited[u] = true;
    ans = max(ans, values[u]);

    for (long long v : adj[u]) {
        if (!visited[v]) {
            dfs(v, ans, visited);
        }
    }
}

void solve() {
    cin >> n;
    for (long long i = 1; i <= n; i++) {
        cin >> t[i].value;
        t[i].idx = i;
        values[i] = t[i].value;
    }

    sort(t + 1, t + 1 + n, sapxep);

    for (long long i = 1; i < n; i++) {
        long long u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    long long res = 0;
    vector<vector<bool>> visitedEdge(n + 1, vector<bool>(n + 1, false));

    for (long long i = 1; i <= n; i++) {
        long long u = t[i].idx;
        for (long long v : adj[u]) {
            if (visitedEdge[u][v]) continue;

            visitedEdge[u][v] = visitedEdge[v][u] = true;

            // Tạm thời gỡ bỏ cạnh
            adj[u].erase(remove(adj[u].begin(), adj[u].end(), v), adj[u].end());
            adj[v].erase(remove(adj[v].begin(), adj[v].end(), u), adj[v].end());

            long long ans1 = values[u], ans2 = values[v];
            vector<bool> visited(n + 1, false);
            dfs(u, ans1, visited);
            fill(visited.begin(), visited.end(), false);
            dfs(v, ans2, visited);

            res += ans1 + ans2;

        }
    }

    cout << res << '\n';
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 30
• Subtask 4: 0 / 60