Submission #998766

#	Time	Username	Problem	Language	Result	Execution time	Memory
998766		ZeroCool	Seesaw (JOI22_seesaw)	C++14	100 / 100	73 ms	16328 KiB

seesaw

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

#define int long long
#define ll long long
#define ar array
#define ld long double

const int N = 2e5 + 20;
const int MOD = 1e9 + 7;
const int LOG = 30;

int A[N];

ld get(int l,int r){
	return (ld)(A[r] - A[l-1]) / (r - l + 1);
}

signed main(){ios::sync_with_stdio(false);cin.tie(0);	
	int n;
	cin>>n;
	for(int i =1;i<=n;i++){
		cin>>A[i];
		A[i] += A[i-1];
	}
	
	int l = 1;
	int r = n;
	vector<ar<ld, 3> > v;
	while(l != r){
		if(get(l, r - 1) >= get(1, n)){
			r--;
			
		}else l++;
		v.push_back({get(l, r), l, r});
	}
	sort(v.begin(), v.end());
	reverse(v.begin(), v.end());
	ld ans = 1e9;
	ld mn = get(1, n);
	for(auto [cen, l, r]: v){
		ans = min(ans, cen - mn);
		mn = min(mn, get(l -1, r- 1));	
	}
	ans = min(ans, get(1, n) - mn);
	cout<<setprecision(12)<<fixed<<ans<<'\n';
}

Compilation message (stderr)

seesaw.cpp: In function 'int main()':
seesaw.cpp:35:27: warning: narrowing conversion of 'l' from 'long long int' to 'long double' [-Wnarrowing]
   35 |   v.push_back({get(l, r), l, r});
      |                           ^
seesaw.cpp:35:30: warning: narrowing conversion of 'r' from 'long long int' to 'long double' [-Wnarrowing]
   35 |   v.push_back({get(l, r), l, r});
      |                              ^
seesaw.cpp:41:11: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   41 |  for(auto [cen, l, r]: v){
      |           ^

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