#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
struct Frac{
ll a, b;
Frac(){}
Frac(ll _a, ll _b): a(_a), b(_b) {}
long double ch()const{return (long double) a / b;}
bool operator < (const Frac &F) const{
return (__int128)a * F.b < (__int128)b * F.a;
}
};
int n, a[200200], idx[200200];
set<pair<Frac, int>> st;
ll S[200200];
Frac val(int l, int r){return Frac(S[r] - S[l-1], r-l+1);}
int main(){
scanf("%d", &n);
for (int i=1;i<=n;i++) scanf("%d", a+i);
for (int i=1;i<=n;i++) S[i] = S[i-1] + a[i];
for (int d=0;d<=n-1;d++){
int l = 1, r = n-d;
idx[d] = 1;
while(l<=r){
int m = (l+r)>>1;
if (val(m, m+d) < val(1, n)) idx[d] = m, l = m+1;
else r = m-1;
}
st.emplace(val(idx[d], idx[d]+d), d);
}
long double ans = 1e18;
while(!st.empty()){
ans = min(ans, st.rbegin()->first.ch() - st.begin()->first.ch());
auto [x, d] = *st.begin();
st.erase(st.begin());
if (idx[d]+1+d > n) break;
st.emplace(val(idx[d]+1, idx[d]+d+1), d);
}
printf("%.15Lf\n", ans);
return 0;
}
Compilation message
seesaw.cpp: In function 'int main()':
seesaw.cpp:24:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
24 | scanf("%d", &n);
| ~~~~~^~~~~~~~~~
seesaw.cpp:25:33: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
25 | for (int i=1;i<=n;i++) scanf("%d", a+i);
| ~~~~~^~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
212 KB |
Output is correct |
7 |
Correct |
1 ms |
212 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
212 KB |
Output is correct |
7 |
Correct |
1 ms |
212 KB |
Output is correct |
8 |
Correct |
1 ms |
468 KB |
Output is correct |
9 |
Correct |
1 ms |
468 KB |
Output is correct |
10 |
Correct |
1 ms |
468 KB |
Output is correct |
11 |
Correct |
1 ms |
468 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
212 KB |
Output is correct |
7 |
Correct |
1 ms |
212 KB |
Output is correct |
8 |
Correct |
1 ms |
468 KB |
Output is correct |
9 |
Correct |
1 ms |
468 KB |
Output is correct |
10 |
Correct |
1 ms |
468 KB |
Output is correct |
11 |
Correct |
1 ms |
468 KB |
Output is correct |
12 |
Correct |
194 ms |
15936 KB |
Output is correct |
13 |
Correct |
168 ms |
17876 KB |
Output is correct |
14 |
Correct |
164 ms |
17788 KB |
Output is correct |
15 |
Correct |
169 ms |
17864 KB |
Output is correct |
16 |
Correct |
157 ms |
17880 KB |
Output is correct |