Submission #871009

#	Time	Username	Problem	Language	Result	Execution time	Memory
871009		Trisanu_Das	Seesaw (JOI22_seesaw)	C++17	67 / 100	2041 ms	4712 KiB

seesaw

#include <bits/stdc++.h> 
using namespace std;
 
int A[200005], n;
long long pref[200005];
long double ans;
 
long double calc(int l, int r) {
	return (long double)(pref[r] - pref[l - 1]) / (r - l + 1);
}
 
long double solve(long double max_r) {	
	int l = 1, r = n;
	long double tl = calc(l, r), tr = calc(l, r);
	while (l < r) {
		long double tll = min(tl, calc(l + 1, r)), tlr = max(tr, calc(l + 1, r));
		if (tlr <= max_r) l++;
		else r--;
		tl = min(tl, calc(l, r));
		tr = max(tr, calc(l, r));
		if (tr - tl >= ans) return tr - tl;
	}
	return tr - tl;
}
 
int main() {
	ios_base::sync_with_stdio(false); cin.tie(0);
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> A[i];
		pref[i] = pref[i - 1] + A[i];
	}
	ans = A[n] - A[1];
	for (int l = 1; l <= n; l++) for (int r = l; r <= n; r++) ans = min(ans, solve(calc(l, r)));
	cout << setprecision(10) << fixed << ans << '\n';
}

Compilation message (stderr)

seesaw.cpp: In function 'long double solve(long double)':
seesaw.cpp:16:15: warning: unused variable 'tll' [-Wunused-variable]
   16 |   long double tll = min(tl, calc(l + 1, r)), tlr = max(tr, calc(l + 1, r));
      |               ^~~

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