How to check if all elements in an array are equal using recursion in Python?-CodePudding

I am practising recursion and am not sure why my code is failing.

def isEqual(arr, n):
    if(n==1):
        return arr[n]
    return arr[n-1]==isEqual(arr, n-1)

The logic is quite generic. I assume that I have a method that can check whether all elements in my array until length n-1 are equal, isEqual(arr, n-1). Next, I check if the nth element is equal to the preceding elements using arr[n-1]==isEqual(arr, n-1).

However, the code fails for basic test cases such as -

arr = [5,5,5,5,5,5]
isEqual(arr, len(arr))

Could someone point me towards where I am going wrong?

CodePudding user response：

You are mixing up returning a value v.s equality check. There are many ways to correct it, but here is an example

def isEqual(arr, n):
    if(n<=0):
        return True
    return arr[n-1]==arr[n] and isEqual(arr,n-1)
arr = [5,5,5,5,5,5]
print(isEqual(arr, len(arr)-1))
brr = [1,2,3,4,5]
print(isEqual(brr, len(brr)-1))
crr=[False]*5
print(isEqual(crr, len(crr)-1))