If this is out of school, totally understand, but thought I would see if anybody could point me in the right direction within the rules of the competition. I've got a working solution in a reasonable amount of time for the base euler 152 problem with the fraction of 1/2 for up to 100, but am still failing most of the test cases. What are some of the corner cases to consider in tracking down the missing combinations?

What is time/memory constraint for this problem ?

can anyone help me make this code faster

class Permutation {

static int answer = 0;
static void combinationUtil(int arr[], int n, int r, int index,
                            int data[], int i,int d)
{
    if (index == r)
    {
        float k =0;
        for (int j=0; j<r; j++)
        {
            k += 1/(Math.pow(data[j],2));
        }
        if((float)1/d == k)
            answer++;
    return;
    }

    if (i >= n)
    return;

    data[index] = arr[i];
    combinationUtil(arr, n, r, index+1, data, i+1,d);


    combinationUtil(arr, n, r, index, data, i+1,d);
}

static void printCombination(int arr[], int n,int d)
{
    int r=0;
    while(r <= n)
    {
        int data[]=new int[r];
        combinationUtil(arr, n, r, 0, data, 0,d);
        r++;
    }
}

public static void main (String[] args) {
    Scanner s = new Scanner(System.in);
    int d = s.nextInt();
    int n = s.nextInt();
    int arr[] = new int[n-1];
    for(int i = 2;i <= n;i++)
    {
        arr[i-2] = i;
    }
    printCombination(arr, n-1,d);
    System.out.println(answer);
}

}

I didnt get what the question is?

import java.io.; import java.util.; import java.text.; import java.math.; import java.util.regex.*; public class Solution { public static void main(String[] args) { Scanner sc=new Scanner(System.in); long n=sc.nextInt(); long sum=0; for(long ni=1;ni<=n;ni++) { for(long a=1;a<=ni;a++) { for(long b=0;b

             }  

        }
    }
}
System.out.println(sum);

} }