C :

#include <stdio.h>
#include <stdlib.h>
#define maxn 2010
#define INF 1000000000
#define min(A,B) ((A)<(B))?(A):(B)
int A[maxn], dp[2][maxn];

int cmp(const void * a, const void * b) {
return ( *(int*)a-*(int*)b);
}

int main()
{
    int n, k;
    while(scanf("%d%d",&n,&k) != EOF) {
        if(n==0&&k==0) break;
        for(int i = 1;i <= n; i++)scanf("%d",&A[i]);
        for(int i = 0;i <= 1; i++){
            for(int j  = 0;j <= n; j++){
                dp[i][j]=INF;
            }
        }
        for(int i = 0;i < 2; i++)dp[i][0]=0;
        qsort(A+1,n,sizeof(int),cmp);
        for(int i = 2;i <= n; i++) {
            for(int j = k;j >= 1; j--){
                int temp = dp[1][j];
                dp[1][j]=min(dp[0][j-1]+(A[i-1]-A[i])*(A[i-1]-A[i]),dp[1][j]);
                dp[0][j]=temp;
            }
        }
        printf("%d\n",dp[1][k]);
    }
    return 0;
}

C++ :

#include <stdio.h>
int n,k,b[2222][1111];
int run()
{
	int i,j,a[2222],s,l;
	for(i=1;i<=n;i++)
		scanf("%d",&a[i]);
	for(i=1;i<=n;i++)
		for(j=i+1;j<=n;j++)
			if(a[i]>a[j])
			{
				l=a[i];
				a[i]=a[j];
				a[j]=l;
			}
	for(i=0;i<=n;i++)
		for(j=0;j<=k;j++)
			b[i][j]=-1;
	b[0][0]=0;
	for(i=0;i<=n;i++)
		for(j=0;j<=k;j++)
			if(b[i][j]!=-1)
			{
				s=b[i][j]+(a[i+1]-a[i+2])*(a[i+1]-a[i+2]);
				if((b[i+2][j+1]==-1)||(b[i+2][j+1]>s))
					b[i+2][j+1]=s;
				if((b[i+1][j]==-1)||(b[i+1][j]>b[i][j]))
					b[i+1][j]=b[i][j];
			}
	printf("%d\n",b[n][k]);
}
int main()
{
	scanf("%d%d",&n,&k);
	while(n!=0)
	{
		run();
		n=0;
		scanf("%d%d",&n,&k);
	}
	return 0;
}