#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif
const int N = 2e5 + 5;
int n;
int a[N], fre[N];
long long pf[N];
double qry(int l, int r) {
return (double) (pf[r] - pf[l - 1]) / (r - l + 1);
}
int main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
cin >> n;
for (int i = 1; i <= n; ++i) {
cin >> a[i];
pf[i] = pf[i - 1] + a[i];
}
double A = qry(1, n);
vector<pair<double, int>> cands = {{A, n}};
for (int l = 1; l < n; ++l) {
int L = 1, R = n - l + 1, p = 0;
while (L <= R) {
int md = (L + R) / 2;
if (qry(md, md + l - 1) < A) {
p = md;
L = md + 1;
} else {
R = md - 1;
}
}
cands.push_back({qry(p, p + l - 1), l});
cands.push_back({qry(p + 1, p + l), l});
}
sort(cands.begin(), cands.end());
double res = 1e9;
for (int i = 0, j = 0, cnt = 0; i < cands.size(); ++i) {
while (j < cands.size() && cnt < n) {
cnt += !fre[cands[j++].second]++;
}
if (cnt == n) {
res = min(res, cands[j - 1].first - cands[i].first);
}
cnt -= !--fre[cands[i].second];
}
cout << fixed << setprecision(12) << res;
return 0;
}
Compilation message
seesaw.cpp: In function 'int main()':
seesaw.cpp:47:37: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<double, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
47 | for (int i = 0, j = 0, cnt = 0; i < cands.size(); ++i) {
| ~~^~~~~~~~~~~~~~
seesaw.cpp:48:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<double, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
48 | while (j < cands.size() && cnt < n) {
| ~~^~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
344 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
344 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
1 ms |
604 KB |
Output is correct |
9 |
Correct |
1 ms |
604 KB |
Output is correct |
10 |
Correct |
1 ms |
604 KB |
Output is correct |
11 |
Correct |
1 ms |
604 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
344 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
1 ms |
604 KB |
Output is correct |
9 |
Correct |
1 ms |
604 KB |
Output is correct |
10 |
Correct |
1 ms |
604 KB |
Output is correct |
11 |
Correct |
1 ms |
604 KB |
Output is correct |
12 |
Correct |
49 ms |
15568 KB |
Output is correct |
13 |
Correct |
48 ms |
15056 KB |
Output is correct |
14 |
Correct |
48 ms |
15560 KB |
Output is correct |
15 |
Correct |
55 ms |
14540 KB |
Output is correct |
16 |
Correct |
48 ms |
14288 KB |
Output is correct |