CODEWITHSUNDEEP
javaalgorithmsortingrecursion
akisonlyforu
akisonlyforu

Reputation: 332

Why is my function not giving correct output?

My function checks that whether an array is sorted or not using recursion. Unfortunately, it is returning false for every array.

Function call : sorted(a,0,a.length) where a[] = {1,2,3}; 

boolean sorted(int[] a , int s , int n)
{
    if(s+1==n)
        return true ;
    if(a[s]<=a[s+1])
        sorted(a,s+1,n);
    return false ;
}

Upvotes: 1

Views: 64

Answers (2)

Mureinik
Mureinik

Reputation: 311448

You are ignoring the result of the recursive call to sorted. Just return it, and you should be fine:

boolean sorted(int[] a , int s , int n)
{
    if(s+1==n)
        return true ;
    if(a[s]<=a[s+1])
        return sorted(a,s+1,n); // Here!      
    return false ;
}

Upvotes: 4

MBo
MBo

Reputation: 80197

You don't use result of recursive call. Perhaps it may look like

 if(a[s]<=a[s+1])
      return sorted(a,s+1,n)
 else
     return false;

or (if Java uses fast evaluation of complex conditions):

return (a[s]<=a[s+1]) && (sorted(a,s+1,n))

Upvotes: 1

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