hdu 1412

#include <iostream>
#include <stdlib.h>
#include <memory.h>

using namespace std;
const int INF = 1000000000;
int d[2005][1005];
int min(int a,int b){
    return a<b?a:b;
}
int cmp(const void *a,const void*b){
    return *(int *)a - *(int *)b;
}
int main(){
    int n,k,a[2005];
    while(~scanf("%d%d",&n,&k)){
          for(int i=0;i<=n;i++){
                  for(int j=0;j<=k;j++){
                          d[i][j] = INF;
                  }
          }
          for(int i=1;i<=n;i++){
                  scanf("%d",&a[i]);
          }
          for(int i=0;i<=n;i++){
                  d[i][0] = 0;
          }
          qsort(a,n+1,sizeof(a[0]),cmp);
          for(int i=2;i<=n;i++){
                  for(int j=1;j<=i/2;j++){
                          //if(i>2*j)
                          d[i][j] = min(d[i-1][j],d[i-2][j-1]+(a[i]-a[i-1])*(a[i]-a[i-1]));
                          //if(i == 2*j)
                          //d[i][j] = d[i-2][j-1]+(a[i]-a[i-1])*(a[i]-a[i-1]);
                  }
          }
          printf("%d\n",d[n][k]);
    }
    return 0;
}