1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include <string.h>
 4 
 5 #define MAXN 2005
 6 #define INF  0x3fffffff
 7 int dp[MAXN][MAXN];
 8 int buf[MAXN];
 9 int deg[MAXN];
10 
11 int mymin(int a, int b) {
12     return (a<b) ? a:b;
13 }
14 
15 int comp(const void *a, const void *b) {
16     return *(int *)a - *(int *)b;
17 }
18 
19 int main() {
20     int n, m, k;
21     int i, j;
22 
23     while (scanf("%d %d", &n, &k) != EOF) {
24         for (i=1; i<=n; ++i)
25             scanf("%d", &buf[i]);
26         qsort(buf+1, n, sizeof(int), comp);
27         m = 1;
28         for (i=2; i<=n; ++i)
29             deg[m++] = (buf[i]-buf[i-1])*(buf[i]-buf[i-1]);
30 
31         for (i=0; i<=n; ++i) {
32             dp[i][0] = 0;
33             for (j=1; j<=k; ++j) {
34                 dp[i][j] = INF;
35             }
36         }
37 
38         for (i=2; i<=n; ++i) {
39             for (j=1; j+j<=i; ++j) {
40                 dp[i][j] = mymin(dp[i-2][j-1]+deg[i-1], dp[i-1][j]);
41             }
42         }
43         printf("%d\n", dp[n][k]);
44     }
45 
46     return 0;
47 }