#include <bits/stdc++.h>
#define IO_OP std::ios::sync_with_stdio(0); std::cin.tie(0);
#define F first
#define S second
#define V vector
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define SZ(v) int((v).size())
#define ALL(v) (v).begin(), (v).end()
using namespace std;
typedef long long ll;
typedef pair<int, int> pi;
typedef V<int> vi;
typedef long double db;
string _reset = "\u001b[0m", _yellow = "\u001b[33m", _bold = "\u001b[1m";
void DBG() { cerr << "]" << _reset << endl; }
template<class H, class...T> void DBG(H h, T ...t) {
cerr << to_string(h);
if(sizeof ...(t)) cerr << ", ";
DBG(t...);
}
#ifdef CHEISSMART
#define debug(...) cerr << _yellow << _bold << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define debug(...)
#endif
const int INF = 1e9 + 7, N = 2e5 + 6;
const ll oo = 1e18;
int a[N];
ll p[N];
signed main()
{
IO_OP;
cout << fixed << setprecision(12);
int n;
cin >> n;
for(int i = 1; i <= n; i++) {
cin >> a[i];
p[i] = p[i - 1] + a[i];
}
V<db> aux;
for(int i = 1; i <= n; i++) {
for(int j = i; j <= n; j++) {
aux.PB(db(p[j] - p[i - 1]) / (j - i + 1));
}
}
sort(ALL(aux));
aux.resize(unique(ALL(aux)) - aux.begin());
auto go = [&] (double mn) {
V<V<db>> dp(n + 1, V<db>(n + 1, oo));
for(int len = 1; len <= n; len++) {
for(int i = 1; i + len - 1 <= n; i++) {
int j = i + len - 1;
db tt = db(p[j] - p[i - 1]) / (j - i + 1);
if(tt >= mn) {
if(i == j)
dp[i][j] = tt;
else {
dp[i][j] = max(min(dp[i][j - 1], dp[i + 1][j]), tt);
}
}
}
}
return dp[1][n] - mn;
};
int pos = find(ALL(aux), db(p[n]) / n) - aux.begin();
int lb = 0, rb = pos - 1;
while(lb <= rb) {
int mb = (lb + rb) / 2;
if(go(aux[mb]) < go(aux[mb + 1])) rb = mb - 1;
else lb = mb + 1;
}
cout<< go(aux[lb]) << '\n';
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
212 KB |
Output is correct |
| 2 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
212 KB |
Output is correct |
| 2 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
212 KB |
Output is correct |
| 2 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
212 KB |
Output is correct |
| 2 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
