Submission #342960

#	Time	Username	Problem	Language	Result	Execution time	Memory
342960		alrad	Putovanje (COCI20_putovanje)	C++17	110 / 110	214 ms	42732 KiB

putovanje

#include <bits/stdc++.h>

using namespace std;

using ld = long double;
using ull = unsigned long long;

/*
#pragma comment(linker, "/STACK:256000000")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("-O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
*/

template <class T> inline T gcd(T a , T b) { return !a ? b : gcd(b % a , a); }
template <class T> inline T lcm(T a , T b) { return (a * b) / gcd(a , b) ; }

mt19937 rnd(time(0));

#define all(x) x.begin(), x.end()
#define debug(x) { cerr << #x << " = " << x << endl; }

const int N = 2e5 + 2;
const int LOG = 20;

int timer = 0, tin[N], tout[N], prefix[N], dp[N];
vector<vector<pair<int, int>>> g(N, vector<pair<int, int>>());
vector<vector<int>> up(N, vector<int>(LOG, 1));

void dfs1(int v, int p = 1) {
  tin[v] = timer++;
  up[v][0] = p;
  for (int i = 1; i < LOG; i++) {
    up[v][i] = up[up[v][i - 1]][i - 1];
  }
  for (auto edge : g[v]) {
    int to = edge.first;
    if (to != p) {
      dfs1(to, v);
    }
  }
  tout[v] = timer++;
}

bool ancestor(int a, int b) {
  return (tin[a] <= tin[b] && tout[a] >= tout[b]);
}

int lca(int a, int b) {
  if (ancestor(a, b)) {
    return a;
  }
  if (ancestor(b, a)) {
    return b;
  }
  for (int i = LOG - 1; i >= 0; i--) {
    if (!ancestor(up[a][i], b)) {
      a = up[a][i];
    }
  }
  return up[a][0];
}

void dfs2(int v, int p = -1, int in = -1) {
  for (auto edge : g[v]) {
    int to = edge.first, num = edge.second;
    if (to != p) {
      dfs2(to, v, num);
      prefix[v] += prefix[to];
    }
  }
  if (in != -1) {
    dp[in] = prefix[v];
  }
}

void solve() {
  int n;
  cin >> n;
  vector<int> cost1(n), cost2(n);
  for (int i = 1; i < n; i++) {
    int u, v;
    cin >> u >> v >> cost1[i] >> cost2[i];
    g[u].push_back({v, i});
    g[v].push_back({u, i});
  }
  dfs1(1);
  for (int i = 1; i < n; i++) {
    prefix[i]++;
    prefix[i + 1]++;
    prefix[lca(i, i + 1)] -= 2;
  }
  dfs2(1);
  long long ans = 0ll;
  for (int i = 1; i < n; i++) {
    ans += min(1ll * cost2[i], cost1[i] * 1ll * dp[i]);
  }
  cout << ans << '\n';
  return;
}

signed main() {
  ios_base :: sync_with_stdio(0);
  cin.tie(0) , cout.tie(0);
  int t = 1;
  while (t-- > 0) {
    solve();
  }
  return 0;
}

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