1 #include <iostream>
2 #include <iomanip>
3 #include <cmath>
4 using namespace std;
5
6 int N;
7 int K;
8 double num[10001];
9
10 int calc(double len)
11 {
12 int numK= 0;
13 for(int i = 0; i < N; ++i)
14 {
15 numK += (int)(num[i] / len);
16 }
17 return numK;
18 }
19
20 double solve()
21 {
22 double low = 0;
23 double upper = 100000;
24 int count = 0;
25 double mid;
26 int numK;
27 while(count < 100)
28 {
29 mid = (low + upper) / 2;
30 numK = calc(mid);
31 if(numK >= K)
32 low = mid;
33 else
34 upper = mid;
35 ++count;
36 }
37 return mid;
38 }
39
40 int main()
41 {
42 //基于二分法的思想实现
43 cin >> N >> K;
44 for(int i = 0; i < N; ++i)
45 cin >> num[i];
46 //这里floor很重要
47 cout << setiosflags(ios::fixed) << setprecision(2) << floor(solve()*100)/100 << endl;
48 return 0;
49 }
