#include <bits/stdc++.h> using namespace std; //This is Grok code. I am using this website to test different AI's and their abilities to solve IOI problems. Please understand. I do not mean to cheat. Just trying to get a good grade on my science project. pair<vector<int>, long long> transaction(long long M); void buy_souvenirs(int N, long long P0) { vector<long long> P(N); P[0] = P0; // Step 1: Discover all prices P[1], P[2], ..., P[N-1] using binary search for (int i = 1; i < N; ++i) { long long low = 1; long long high = P[i - 1] - 1; long long found = -1; while (low <= high) { long long mid = low + (high - low) / 2; auto [types, remaining] = transaction(mid); // Check if we got any type >= i bool got_high = false; for (int t : types) { if (t >= i) { got_high = true; break; } } if (got_high) { // P[i] <= mid found = mid; high = mid - 1; } else { // P[i] > mid low = mid + 1; } } P[i] = found; } // Step 2: Buy exactly i souvenirs of type i (for i = 1 to N-1) // Using transaction(P[i]) exactly i times gives exactly one type i each time for (int i = 1; i < N; ++i) { for (int cnt = 0; cnt < i; ++cnt) { transaction(P[i]); } } }