1 #include <iostream>
2 #include <vector>
3 #include <algorithm>
4 using namespace std;
5
6 unsigned int N;
7 unsigned int C;
8 vector<int> x;
9 int stall;
10
11 int main()
12 {
13 /***************************************************/
14 //input and preprocessing
15
16 cin >> N >> C;
17 for(int i = 0; i < N; ++i)
18 {
19 int temp;
20 cin >> temp;
21 x.push_back(temp);
22 }
23 sort(x.begin(), x.end());
24
25
26 /***************************************************/
27 //solver
28 int lower = 0;
29 int upper = 1000000000;
30 int mid;
31 while(upper - lower > 1)
32 {
33 mid = (upper + lower) / 2;
34
35 /***************************************************/
36 //calc
37 stall = 1;
38 for(int i = 0, j = 0; i < x.size(); )
39 {
40 if(x[i] - x[j] >= mid)
41 {
42 ++stall;
43 j = i;
44 ++i;
45 }
46 else
47 {
48 ++i;
49 }
50
51 }
52 //end calc
53 /***************************************************/
54 if(stall >= C)
55 lower = mid;
56 else
57 upper = mid;
58 }
59
60 /***************************************************/
61 //output
62
63 cout << lower << endl;
64 return 0;
65 }
