Submission #897374

#	Time	Username	Problem	Language	Result	Execution time	Memory
897374		NeroZein	Designated Cities (JOI19_designated_cities)	C++17	16 / 100	188 ms	43312 KiB

designated_cities

#include "bits/stdc++.h"
using namespace std;

#ifdef Nero
#include "Deb.h"
#else
#define deb(...)
#endif

const int N = 2e5 + 5;

long long f[N];
long long ans[N];
long long dist[N];
vector<pair<int, int>> g[N];
pair<long long, long long> dp[N];

void dfs1(int v, int p) {
  long long mx = 0, mx2 = 0;
  for (auto [u, w] : g[v]) {
    if (u == p) continue;
    dist[1] += w;
    dfs1(u, v); 
    mx2 = max(mx2, dp[u].first + w); 
    if (mx2 > mx) swap(mx, mx2);
  }
  dp[v] = make_pair(mx, mx2);
}

void dfs2(int v, int p, long long up) {
  auto [mx, mx2] = dp[v];
  for (auto [u, w] : g[v]) {
    if (u == p) {
      dist[v] += w;
      up += w; 
    }
  }
  f[v] = max(mx, up);
  for (auto [u, w] : g[v]) {
    if (u == p) continue;
    dist[u] = dist[v] - w; 
    long long nup = (mx == dp[u].first + w ? mx2 : mx);
    nup = max(up, nup);
    dfs2(u, v, nup);
  }
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n;
  cin >> n;
  for (int i = 1; i < n; ++i) {
    int u, v, c, d;
    cin >> u >> v >> c >> d;
    g[u].emplace_back(v, c);
    g[v].emplace_back(u, d); 
  }
  dfs1(1, 0);
  dfs2(1, 0, 0);
  ans[1] = *min_element(dist + 1, dist + 1 + n);
  ans[2] = LLONG_MAX;
  dist[0] = LLONG_MAX;
  int r = 0; 
  for (int i = 1; i <= n; ++i) {
    if (dist[i] - f[i] < dist[r] - f[r]) {
      r = i;
    }
  }
  ans[2] = dist[r] - f[r];
  int q;
  cin >> q;
  while (q--) {
    int e;
    cin >> e;
    cout << ans[e] << '\n'; 
  }
  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