Submission #1127006

#	Time	Username	Problem	Language	Result	Execution time	Memory
1127006		gawr_gura	Seesaw (JOI22_seesaw)	C++20	1 / 100	69 ms	328 KiB

seesaw

#include <bits/stdc++.h>
#define ll long long
using namespace std;


const int N = 1e6 + 5;

int n;
double a[N];

signed main() {
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  #define task "seesaw"
  if(fopen(task ".inp","r")) {
    freopen(task ".inp","r",stdin);
    freopen(task ".out","w",stdout);
  }
  cin >> n;
  for(int i = 1; i <= n; i ++) cin >> a[i];
  double ans = (double)(2e9);
  for(int msk = 0; msk < (1 << n); msk ++) {
    double sum = 0;
    int l = 1, r = n;
    for(int i = 1; i <= n; i ++) sum += a[i];
    double cnt = n;
    double mi = (1.0 * sum) / (1.0 * cnt);
    double mx = (1.0 * sum) / (1.0 * cnt);

    for(int k = 1; k < n; k ++) if(msk >> (k - 1) & 1) {
      sum -= a[r];
      cnt--;
      mx = max(mx, (1.0 * sum) / (1.0 * cnt));
      mi = min(mi, (1.0 * sum) / (1.0 * cnt));
      r --;
    } else {
      sum -= a[l];
      cnt--;
      mx = max(mx, (1.0 * sum) / (1.0 * cnt));
      mi = min(mi, (1.0 * sum) / (1.0 * cnt));
      l ++;
    }
    ans = min(ans, mx - mi);
  }
  cout << setprecision(9) << fixed << ans;

}

Compilation message (stderr)

seesaw.cpp: In function 'int main()':
seesaw.cpp:15:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     freopen(task ".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
seesaw.cpp:16:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     freopen(task ".out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 1 / 1
• Subtask 2: 0 / 33
• Subtask 3: 0 / 33
• Subtask 4: 0 / 33