Submission #530123

#	Time	Username	Problem	Language	Result	Execution time	Memory
530123		4fecta	Designated Cities (JOI19_designated_cities)	C++17	16 / 100	279 ms	46964 KiB

designated_cities

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define int ll
#define ld long double
#define pii pair<int, int>
#define f first
#define s second
#define boost() cin.tie(0), cin.sync_with_stdio(0)

struct edge {
    int u, f, b;
};

const int MN = 200005;

int n, q, u, v, w, x, cost, ans[MN], dp[MN], node[MN];
vector<edge> a[MN];

void dfs1(int cur, int par) {
    for (auto nxt : a[cur]) {
        if (nxt.u == par) continue;
        cost += nxt.f;
        dfs1(nxt.u, cur);
    }
}

void dfs2(int cur, int par) {
    ans[1] = min(ans[1], cost);
    for (auto nxt : a[cur]) {
        if (nxt.u == par) continue;
        cost += nxt.b - nxt.f;
        dfs2(nxt.u, cur);
        cost += nxt.f - nxt.b;
    }
}

void dfs3(int cur, int par) {
    node[cur] = cur;
    for (auto nxt : a[cur]) {
        if (nxt.u == par) continue;
        cost += nxt.b - nxt.f;
        dfs3(nxt.u, cur);
        cost += nxt.f - nxt.b;
        int val = dp[cur] + dp[nxt.u] + nxt.f;
        if (cost - val < ans[2]) {
            ans[2] = cost - val;
            u = node[cur], v = node[nxt.u];
        }
        if (dp[cur] < dp[nxt.u] + nxt.f) {
            dp[cur] = dp[nxt.u] + nxt.f;
            node[cur] = node[nxt.u];
        }
    }
}

void solve1() {
    dfs1(1, 0);
    dfs2(1, 0);
}

void solve_other() {
    dfs3(1, 0);
}

int32_t main() {
    boost();

    memset(ans, 0x3f, sizeof(ans));
    cin >> n;
    for (int i = 1; i < n; i++) {
        cin >> u >> v >> w >> x;
        a[u].push_back({v, w, x});
        a[v].push_back({u, x, w});
    }
    solve1();
    solve_other();
    cin >> q;
    while (q--) {
        cin >> x;
        printf("%lld\n", ans[x]);
    }

    return 0;
}

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