| # | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
|---|---|---|---|---|---|---|---|
| 1320131 | lucas110550 | Souvenirs (IOI25_souvenirs) | C++20 | 0 ms | 0 KiB |
#include <vector>
#include <algorithm>
#include <iostream>
using namespace std;
void buy_souvenirs(int N, long long P0) {
// ------------------------------------------------------------
// 1. Pre-compute Fibonacci numbers up to N+2.
// ------------------------------------------------------------
vector<long long> F;
F.reserve(N + 3);
F.push_back(0); // F[0]
F.push_back(1); // F[1]
for (int k = 2; k <= N + 2; ++k) {
F.push_back(F.back() + F[F.size() - 2]);
}
// ------------------------------------------------------------
// 2. Determine the prices P[1] ... P[N-2] by binary search.
// ------------------------------------------------------------
// P[0] is known. We allocate size N to store indices 0 to N-1.
// Note: Python logic stops filling at P[N-2], so P[N-1] is unused/implicit.
vector<long long> P(N);
P[0] = P0;
for (int i = 1; i < N - 1; ++i) {
long long prev = P[i - 1]; // price of the previous (more expensive) type
int L = N - i + 1; // length of the suffix
// Python: low = (prev - F[L - 1]) // F[L]
// C++ integer division behaves like // for positive numbers.
long long low = (prev - F[L - 1]) / F[L];
if (low < 1) {
low = 1;
}
long long high = prev - 1;
// Binary search
while (low < high) {
long long mid = low + (high - low) / 2;
// Execute transaction
pair<vector<int>, long long> res = transaction(mid);
const vector<int>& bought = res.first;
// Check if i is in bought
bool found = false;
for (int type : bought) {
if (type == i) {
found = true;
break;
}
}
if (found) {
high = mid; // type i is bought -> try smaller M
} else {
low = mid + 1; // type i not bought -> need larger M
}
}
P[i] = low;
}
// ------------------------------------------------------------
// 3. First round of transactions
// ------------------------------------------------------------
vector<int> bought_cnt(N, 0);
for (int i = 1; i < N; ++i) {
long long M = P[i - 1] - 1;
pair<vector<int>, long long> res = transaction(M);
for (int t : res.first) {
if (t < N) { // Bounds check safety
bought_cnt[t]++;
}
}
}
// ------------------------------------------------------------
// 4. Finish the collection
// ------------------------------------------------------------
// For types 1 ... N-2
for (int i = 1; i < N - 1; ++i) {
while (bought_cnt[i] < i) {
transaction(P[i]); // buys exactly one souvenir of type i
bought_cnt[i]++;
}
}
// For smallest type (N-1)
int last_type = N - 1;
while (bought_cnt[last_type] < last_type) {
// buys exactly one souvenir of the last type
transaction(P[N - 2] - 1);
bought_cnt[last_type]++;
}
}