HDU 3480 Division

#include<bits/stdc++.h>
using namespace std;
const unsigned inf =0x3f3f3f3f;
int n,m;
int a[10005];
unsigned K[10005][5005],dp[10005][5005];
int main()
{
    int T;scanf("%d",&T);
    for(int Case=1;Case<=T;++Case)
    {
        scanf("%d%d",&n,&m);
        for(int i=1;i<=n;++i)scanf("%d",a+i);
        sort(a+1,a+n+1);
        for(int i=0;i<=n;++i)for(int j=0;j<=m;++j)K[i][j]=1,dp[i][j]=0;
        for(int i=1;i<=n;++i)
        {
            dp[i][1]=(a[i]-a[1])*(a[i]-a[1]);
            for(int j=2;j<=min(m,i);++j)
            {
                dp[i][j]=inf;
                for(int k=K[i-1][j];k<=i-1;++k)
                {
                    unsigned tmp=dp[k][j-1]+1LL*(a[i]-a[k+1])*(a[i]-a[k+1]);
                    if(tmp<dp[i][j])
                    {
                        K[i][j]=k;
                        dp[i][j]=tmp;
                    }
                }
            }
        }
        printf("Case %d: %d\n",Case,dp[n][m]);
    }
}