제출 #424521

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
424521		tengiz05	Designated Cities (JOI19_designated_cities)	C++17	7 / 100	283 ms	32036 KiB

designated_cities

#include <bits/stdc++.h>
using i64 = long long;
constexpr int N = 2e5;
std::vector<std::pair<int, int>> e[N];
int n, upedge[N];
i64 dp[N];
void dfs(int u, int p) {
    dp[u] = 0;
    for (auto [v, w] : e[u]) {
        if (v == p) {
            upedge[u] = w;
        }
    }
    for (auto [v, w] : e[u]) {
        if (v != p) {
            dfs(v, u);
            dp[u] += dp[v] + upedge[v];
        }
    }
}
i64 ans[N];
void dfs2(int u, int p, i64 car = 0) {
    ans[u] = dp[0] + car;
    for (auto [v, w] : e[u]) {
        if (v != p) {
            dfs2(v, u, car + w - upedge[v]);
        }
    }
}
int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    std::cin >> n;
    i64 sum = 0;
    for (int i = 0; i < n - 1; i++) {
        int u, v, c, d;
        std::cin >> u >> v >> c >> d;
        u--;
        v--;
        e[u].emplace_back(v, c);
        e[v].emplace_back(u, d);
        sum += c + d;
    }
    dfs(0, 0);
    dfs2(0, 0);
    i64 res = *std::max_element(ans, ans + n);
    std::cout << sum - res << "\n";
    return 0;
}

• Subtask 1: 0 / 6
• Subtask 2: 7 / 7
• Subtask 3: 0 / 9
• Subtask 4: 0 / 17
• Subtask 5: 0 / 17
• Subtask 6: 0 / 44