Solution in JAVA

// Complete the getMinimumCost function below. static int getMinimumCost(int k, int[] c) {

    Arrays.sort(c);
    int res=0;
    int m=0;int counter=0;
    int i=c.length-1;
    for(;i>=0;i--)
    {

        if(counter%k==0 && counter>0){
            counter=0;
            m++;
        }
        System.out.println(i+" "+m+" "+counter);
        res=res+(m+1)*c[i];
        counter++;
        System.out.println(res);
    }
    return res;


}