| # | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
|---|---|---|---|---|---|---|---|
| 1188979 | Mamikonm1 | 커다란 상품 (IOI17_prize) | C++20 | 0 ms | 0 KiB |
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
static const int max_q = 10000;
static int n;
static int query_count = 0;
static vector<int> g;
static vector<vector<int> > rank_count;
vector<int> ask(int i) {
query_count++;
if (query_count > max_q) {
cerr << "Query limit exceeded" << endl;
exit(0);
}
if (i < 0 || i >= n) {
cerr << "Bad index: " << i << endl;
exit(0);
}
vector<int> res(2);
res[0] = rank_count[g[i] - 1][i + 1];
res[1] = rank_count[g[i] - 1][n] - res[0];
return res;
}
int find_best(int n) {
int l = 1, r = n + 1, md, ans = -1;
while (l + 1 < r) {
md = r + l >> 1;
vector<int>cur = ask(md);
if (cur[0])
r = md;
else if (cur[0])
l = md;
else {
ans = md;
break;
}
}
return ans;
}
int main() {
cin >> n;
g.resize(n);
for (int i = 0; i < n; i++) {
cin >> g[i];
if (g[i] < 1) {
cerr << "Invalid rank " << g[i] << " at index " << i << endl;
exit(0);
}
}
int max_rank = *max_element(g.begin(), g.end());
rank_count.resize(max_rank + 1, vector<int>(n + 1, 0));
for (int r = 0; r <= max_rank; r++) {
for (int i = 1; i <= n; i++) {
rank_count[r][i] = rank_count[r][i - 1];
if (g[i - 1] == r)
rank_count[r][i]++;
}
}
for (int i = 0; i <= n; i++)
for (int r = 1; r <= max_rank; r++)
rank_count[r][i] += rank_count[r - 1][i];
int res = find_best(n);
cout << res << endl << "Query count: " << query_count << endl;
return 0;
}