Submission #1255765

#	Time	Username	Problem	Language	Result	Execution time	Memory
1255765		madamadam3	Souvenirs (IOI25_souvenirs)	C++20	0 / 100	11 ms	420 KiB

souvenirs

#include "souvenirs.h"
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using pi = pair<int, int>;

#define FOR(i, a, b) for (int i = a; i < b; i++)
#define ROF(i, a, b) for (int i = a; i >= b; i--)
#define each(a, x) for (auto &a : x)
#define all(x) (x).begin(), (x).end()
#define bg(x) (x).begin()
#define en(x) (x).end()
#define rev(x) reverse(all(x))
#define sz(x) int((x).size())
#define srt(x) sort(all(x))
#define cnt(a, x) count(all(x), a)
#define trace(x) each(a, (x)) cout << a << " "
#define mp make_pair
#define pb push_back
#define lb lower_bound
#define ub upper_bound

struct DSU {
  int n; vi par, siz;

  DSU() {};
  DSU(int N) {
    n = N; par.resize(n); siz.assign(n, 1);
    iota(all(par), 0);
  }

  int find(int v) {
    if (par[v] == v) return v;
    return par[v] = find(par[v]);
  }

  void unite(int a, int b) {
    a = find(a); b = find(b);
    if (a != b) {
      if (siz[a] < siz[b]) swap(a, b);
      par[b] = a;
      siz[a] += siz[b];
    }
  }
};

using R = pair<vi, ll>;
const ll INF = 4e18;

int n;
vi bought; vl price, low, high;

R transact(ll money) {
  auto res = transaction(money);
  for (auto &el : res.first) {
    bought[el]++;
  }
  
  return res;
}

vl actual = {89, 55, 34, 21, 13, 8, 5, 3, 2, 1};
void buy_souvenirs(int N, ll P0) {
  n = N;
  bought.assign(n, 0); price.assign(n, -1); low.assign(n, INF); high.assign(n, -INF);
  price[0] = P0; low[0] = P0; high[0] = P0;

  FOR(i, 1, n) { // assume we always know price[i-1]
    low[i] = (low[i-1] + 1) / 2;
    high[i] = (2 * high[i-1]) / 3;
  }

  auto r1 = transact(high[n-1]);
  // if (sz(r1.first) != 1) exit(1);
  if (r1.first[0] != n-1 && r1.first[0] != n-2) exit(2);

  int start = n - 2;
  if (r1.first[0] == n-1) {
    price[n-1] = high[n-1] - r1.second;
  } else {
    price[n-2] = high[n-1] - r1.second;
    auto r2 = transact(price[n-2] - 1);
    price[n-1] = (price[n-2]-1) - r2.second;
    start = n - 3;
  }

  ROF(i, start, 1) {
    ll pv = price[i+1];

    auto r = transact(2*pv);
    ll cost = (2*pv) - r.second;
    for (auto &el : r.first) {
      if (price[el] == -1) continue;
      cost -= price[el];
    }

    price[i] = cost;
  }

  // cerr << "Actual:\tLow:\tHigh:\n";
  // FOR(i, 0, n) {
  //   cerr << actual[i] << "\t" << low[i] << "\t" << high[i] << "\n";
  // }

  // while (bought[n-1] < n-1) {
  //   transact(price[n-2] - 1);
  // }

  FOR(i, 0, n) {
    if (price[i] == -1) continue;
    while (bought[i] < i) {
      transact(price[i]);
    }
  }
}

• Subtask 0: 0 / 0
• Subtask 1: 0 / 4
• Subtask 2: 0 / 3
• Subtask 3: 0 / 14
• Subtask 4: 0 / 18
• Subtask 5: 0 / 28
• Subtask 6: 0 / 33