Submission #863828

#	Time	Username	Problem	Language	Result	Execution time	Memory
863828		browntoad	Designated Cities (JOI19_designated_cities)	C++14	7 / 100	173 ms	35100 KiB

designated_cities

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define int ll
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define REP(i, n) FOR(i, 0, n)
#define REP1(i, n) FOR(i, 1, n+1)
#define RREP(i, n) for (int i = (n)-1; i >= 0; i--)
#define pb push_back
#define pii pair<int, int>
#define pip pair<int, pii>
#define f first
#define s second
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) (int)((x).size())
#define endl '\n'

const ll maxn = 3e5+5;
const ll inf = (1ll<<60);
const ll mod = 1e9+7;

int n;
vector<pip> g[maxn];
int cnt = 0, ans = inf;
void dfs(int x, int prev){
    for (auto v:g[x]){
        if (v.f == prev) continue;
        cnt += v.s.f;
        dfs(v.f, x);
    }
}
void dfs2(int x, int prev){
    ans = min(ans, cnt);
    for (auto v:g[x]){
        if (v.f == prev) continue;
        cnt += v.s.s;
        dfs2(v.f, x);
        cnt -= v.s.s;
    }
}
signed main(){
    ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
    cin>>n;
    REP(i, n-1){
        int u, v, c, d; cin>>u>>v>>c>>d;
        g[u].pb({v, {c, d-c}});
        g[v].pb({u, {d, c-d}});
    }
    dfs(1, -1); dfs2(1, -1);
    int q; cin>>q;
    cin>>q;
    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