Submission #331721

#	Time	Username	Problem	Language	Result	Execution time	Memory
331721		VROOM_VARUN	Putovanje (COCI20_putovanje)	C++14	110 / 110	237 ms	40272 KiB

putovanje

/*
ID: varunra2
LANG: C++
TASK: putovanje
*/

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

#ifdef DEBUG
#include "lib/debug.h"
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define debug_arr(...) \
  cerr << "[" << #__VA_ARGS__ << "]:", debug_arr(__VA_ARGS__)
#pragma GCC diagnostic ignored "-Wsign-compare"
//#pragma GCC diagnostic ignored "-Wunused-parameter"
//#pragma GCC diagnostic ignored "-Wunused-variable"
#else
#define debug(...) 42
#endif

#define int long long

#define EPS 1e-9
#define IN(A, B, C) assert(B <= A && A <= C)
#define INF (int)1e9
#define MEM(a, b) memset(a, (b), sizeof(a))
#define MOD 1000000007
#define MP make_pair
#define PB push_back
#define all(cont) cont.begin(), cont.end()
#define rall(cont) cont.end(), cont.begin()
#define x first
#define y second

const double PI = acos(-1.0);
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef map<int, int> MPII;
typedef multiset<int> MSETI;
typedef set<int> SETI;
typedef set<string> SETS;
typedef vector<int> VI;
typedef vector<PII> VII;
typedef vector<VI> VVI;
typedef vector<string> VS;

#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define trav(a, x) for (auto& a : x)
#define sz(x) (int)(x).size()
typedef pair<int, int> pii;
typedef vector<int> vi;
#pragma GCC diagnostic ignored "-Wsign-compare"
// util functions

int n;
VVI adj;

struct lca {
  VVI bin;
  const int bits = 20;
  VI tin, tout;
  int timer = 0;

  void dfs(int u, int v) {
    tin[u] = timer++;
    bin[u][0] = v;
    for (int i = 1; i < bits; i++) {
      int to = bin[u][i - 1];
      if (to != -1)
        bin[u][i] = bin[to][i - 1];
      else
        bin[u][i] = -1;
    }
    for (auto& x : adj[u]) {
      if (x == v) continue;
      dfs(x, u);
    }
    tout[u] = timer++;
  }

  void init() {
    bin.resize(n);
    trav(x, bin) x.resize(bits);
    tin.resize(n);
    tout.resize(n);
    dfs(0, -1);
  }

  bool isAnc(int u, int v) {
    if (u == -1) return true;
    if (v == -1) return false;
    return tin[u] <= tin[v] and tout[u] >= tout[v];
  }

  int getLCA(int u, int v) {
    if (isAnc(u, v)) return u;
    if (isAnc(v, u)) return v;
    for (int i = bits - 1; i >= 0; i--) {
      if (!isAnc(bin[u][i], v)) u = bin[u][i];
    }
    return bin[u][0];
  }

  bool isPar(int u, int v) {
    if (bin[u][0] == v) return true;
    return false;
  }

} lc;

VI pref;
VVI edgs;

void init() {
  pref.resize(n);
  adj.resize(n);
  edgs.resize(n - 1);
  trav(x, edgs) x.resize(4);
}

void dfspref(int u, int v) {
  for (auto& x : adj[u]) {
    if (x == v) continue;
    dfspref(x, u);
    pref[u] += pref[x];
  }
}

int32_t main() {
// #ifndef ONLINE_JUDGE
  // freopen("putovanje.in", "r", stdin);
  // freopen("putovanje.out", "w", stdout);
// #endif
  cin.sync_with_stdio(0);
  cin.tie(0);

  cin >> n;

  init();

  for (int i = 0; i < n - 1; i++) {
    int u, v, c1, c2;
    cin >> u >> v;
    u--, v--;
    adj[u].PB(v);
    adj[v].PB(u);
    cin >> c1 >> c2;
    edgs[i] = {u, v, c1, c2};
  }

  lc.init();

  for (int i = 0; i < n - 1; i++) {
    int u = i;
    int v = i + 1;
    int w = lc.getLCA(u, v);
    pref[u]++;
    pref[v]++;
    pref[w] -= 2;
  }

  dfspref(0, -1);

  int ret = 0;

  for (int i = 0; i < n - 1; i++) {
    int u = edgs[i][0];
    int v = edgs[i][1];
    if (!lc.isPar(u, v)) swap(u, v);
    // par of u is v
    int cnt, cost1, cost2;
    cnt = pref[u];
    cost1 = edgs[i][2];
    cost2 = edgs[i][3];
    ret += min(cnt * cost1, cost2);
  }

  cout << ret << '\n';

  return 0;
}

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