Need help with quicksort

I know this is kind of stupid but I was trying to implement quicksort in Python and it runs into an infinite loop can anyone tell me what's wrong??The partition subroutine works perfectly....The error is in quicksort..Here's the code

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     def QuickSort(A,p,r):
          if p < r:
              q = Partition(A,p,r)
              QuickSort(A,0,q)
              QuickSort(A,q+1,r)

    def Partition(A, l, r):
        p = A[l]
        i = l+1
        for j in range(l+1,r):
            if A[j] < p:
                A[j],A[i] = A[i],A[j]
                i += 1
        A[l],A[i-1] = A[i-1],A[l]
     return A.index(p)

Note by Eddie The Head
3 years, 11 months ago

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def Quicksort(A,p,r):
    if p < r:
        q = Partition(A,p,r)
        Quicksort(A,p,q-1) #Mistake is here
        Quicksort(A,q+1,r)
    return A

I am reasonably sure that this is what would work. @josh silverman, can you confirm?

Trevor B. - 3 years, 11 months ago

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to start, your Quicksort doesn't return anything

Josh Silverman Staff - 3 years, 11 months ago

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Fixed!!Thanks a lot.....It feels so frustrated to do stupid mistakes on a known problem............

Eddie The Head - 3 years, 11 months ago

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@Thaddeus Abiy @Ammar Fathin Sabili @Trevor B. Please help!!CS is one of the subjects that I study the most but failing such a trivial and known question today is driving me mad!

Eddie The Head - 3 years, 11 months ago

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@Chung Gene Keun

Eddie The Head - 3 years, 11 months ago

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