Submission #957605

#	Time	Username	Problem	Language	Result	Execution time	Memory
957605		vjudge1	Putovanje (COCI20_putovanje)	C++17	20 / 110	91 ms	37456 KiB

putovanje

#include <bits/stdc++.h>
#define file_io freopen("input.txt", "r", stdin);freopen("output.txt", "w", stdout);
#define fast_io ios::sync_with_stdio(false);cin.tie(0);
#define what(x) cerr << #x << " is " << x << '\n';
#define kill(x) {cout << x << '\n'; return;}
#define all(x) (x).begin(), (x).end()
#define pii pair<int, int>
#define pb push_back
#define ll long long
#define F first
#define S second
const ll inf = 1e16, mod = 1e9 + 7, delta = 1e9 + 9, SQ = 350, P = 6065621;

using namespace std;

const int N = 2e5 + 10, LG = 21;
int c1[N], c2[N], par[N][LG], yalp[N], h[N], cnt[N], a[N];
vector<pii> adj[N];

void dfs (int v, int p = -1) {
  par[v][0] = p;
  if (v == 1) yalp[v] = -1;
  if (p + 1) h[v] = h[p] + 1;
  for (int i = 1; i < LG; i++)
    if (par[v][i - 1] + 1)
      par[v][i] = par[par[v][i - 1]][i - 1];
  for (auto [u, _]: adj[v])
    if (u - p) dfs(u, v), yalp[u] = _;
}

int lca (int v, int u) {
  if (h[u] < h[v]) swap(u, v);
  for (int i = LG - 1; i >= 0; i--)
    if (par[u][i] + 1 && h[par[u][i]] >= h[v])
      u = par[u][i];
  if (u == v) return v;
  for (int i = LG - 1; i >= 0; i--)
    if (par[v][i] != par[u][i])
      v = par[v][i], u = par[u][i];
  return par[v][0];
}

void diefes (int v, int p = -1) {
  for (auto u: adj[v]) {
    if (u.F - p) {
      diefes(u.F, v);
      cnt[u.S] = a[u.F];
      a[v] += a[u.F];
    }
  }
}

int main () {
  fast_io;
  int n;
  cin >> n;
  memset(par, -1, sizeof par);
  for (int i = 1; i < n; i++) {
    int u, v;
    cin >> u >> v >> c1[i] >> c2[i];
    adj[u].pb({v, i});
    adj[v].pb({u, i});
  }
  dfs(1);
  int cur = 1; 
  for (int i = 2; i <= n; i++) {
    if (i == cur) continue;
    int l = lca(i, cur);
    if (l == i) {
      a[cur]++;
      a[i]--;
    } 
    else if (l == cur) {
      a[i]++;
      a[cur]--;
    }
    else {
      a[i]++;
      a[cur]++;
      a[l] -= 2;
    }
    cur = i;
  }
  diefes(1);
  ll ans = 0;
  for (int i = 1; i < n; i++) 
    ans += min(c2[i], c1[i] * cnt[i]);
  cout << ans << '\n'; 
  return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 0 / 25
• Subtask 3: 0 / 65