Submission #511473

#	Time	Username	Problem	Language	Result	Execution time	Memory
511473		couplefire	Designated Cities (JOI19_designated_cities)	C++17	16 / 100	293 ms	49220 KiB

designated_cities

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

const int N = 200005;

int n, q; ll ans[N];
vector<array<int, 3>> adj[N];

namespace Task1{
    ll sum, cur;

    void dfs1(int v, int p){
        for(auto [u, d1, d2] : adj[v]){
            sum += d2;
            if(u==p) continue;
            cur += d2; 
            dfs1(u, v);
        }
    }

    void dfs2(int v, int p){
        ans[1] = min(ans[1], sum-cur);
        for(auto [u, d1, d2] : adj[v]){
            if(u==p) continue;
            cur -= d2; cur += d1;
            dfs2(u, v);
            cur += d2; cur -= d1;
        }
    }

    void solve(){
        dfs1(0, 0);
        dfs2(0, 0);
    }
}

namespace Task2{
    ll sum, tot, dp[N], best[N];
    int best1, best2;

    void dfs1(int v, int p){
        for(auto [u, d1, d2] : adj[v]){
            sum += d2;
            if(u==p) continue;
            tot += d2;
            dfs1(u, v);
        }
    }

    void dfs2(int v, int p, ll val1, ll val2){
        ll tmp = tot-val1+val2;
        array<ll, 2> mx1 = {0, v}, mx2 = {0, v}; 
        best[v] = v;
        for(auto [u, d1, d2] : adj[v]){
            if(u==p) continue;
            dfs2(u, v, val1+d2, val2+d1);
            if(dp[u]+d1>dp[v])
                dp[v] = dp[u]+d1, best[v] = best[u];
            if(array<ll, 2>{dp[u]+d1, best[u]}>mx1)
                mx2 = mx1, mx1 = {dp[u]+d1, best[u]};
            else if(array<ll, 2>{dp[u]+d1, best[u]}>mx2)
                mx2 = {dp[u]+d1, best[u]};
        }
        if(sum-tmp-mx1[0]-mx2[0]<ans[2])
            best1 = mx1[1], best2 = mx2[1], ans[2] = sum-tmp-mx1[0]-mx2[0];
    }

    void solve(){
        dfs1(0, 0);
        dfs2(0, 0, 0, 0);
    }
}

namespace Task3{
    void solve(){

    }
}

int main(){
    // freopen("a.in", "r", stdin);
    cin.tie(0)->sync_with_stdio(0);
    cin >> n;
    for(int i = 0; i<n-1; ++i){
        int a, b, c, d;
        cin >> a >> b >> c >> d;
        --a; --b;
        adj[a].push_back({b, c, d});
        adj[b].push_back({a, d, c});
    }
    memset(ans, 63, sizeof ans);
    Task1::solve();
    Task2::solve();
    Task3::solve();
    cin >> q;
    while(q--){
        int x; cin >> x;
        cout << ans[x] << '\n';
    }
}

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