Submission #223875

#	Time	Username	Problem	Language	Result	Execution time	Memory
223875		osaaateiasavtnl	Designated Cities (JOI19_designated_cities)	C++14	7 / 100	353 ms	34040 KiB

designated_cities

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define ii pair <int, int>
#define app push_back
#define all(a) a.begin(), a.end()
#define bp __builtin_popcount
#define ll long long
#define mp make_pair
#define f first
#define s second
#define Time (double)clock()/CLOCKS_PER_SEC

const int N = 2e5 + 7;
vector <ii> g[N];
int sum[N];
void dfs1(int u, int p) {
    for (auto e : g[u]) {
        int v = e.f, c = e.s;
        if (v != p) {
            dfs1(v, u);
            sum[u] += sum[v] + c;
        }   
    }   
}   
const int INF = 1e18;
int ans = INF;
void dfs2(int u, int p, int up) {
    for (auto e : g[u]) {
        int v = e.f, c = e.s;
        if (v == p) {
            up += c;
        }   
    }   
    ans = min(ans, up + sum[u]);
    for (auto e : g[u]) {
        int v = e.f, c = e.s;
        if (v != p) {
            dfs2(v, u, up + sum[u] - sum[v] - c);
        }   
    }   
}   

signed main() {
    #ifdef HOME
    freopen("input.txt", "r", stdin);
    #else
    #define endl '\n'
    ios_base::sync_with_stdio(0); cin.tie(0);
    #endif
    int n;
    cin >> n;
    for (int i = 0; i < n - 1; ++i) {
        int u, v, a, b;
        cin >> u >> v >> a >> b;
        g[u].app(mp(v, a));
        g[v].app(mp(u, b));
    }   
    dfs1(1, 1);
    dfs2(1, 1, 0);
    cout << ans << endl;
}

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