int solve(int sindex,int eindex,int k,int n){
    int distincts = 0,i;
    if(k == n){
                return (number of distinct elements from sindex to eindex);
    }
    else{
            return 1 + minimum(solve(sindex+1,eindex,k,n-1),
                solve(sindex,eindex-1,k,n-1));
    }
}