Quicksort class implementation

quicksort.py

    
def quicksort(arr):
    p = 0
    r = len(arr) - 1
    solve_recursive(arr,p,r)
        
def solve_recursive(arr,p,r):
    if(p<r):
        q = partition(arr,p,r)
        solve_recursive(arr,p,q-1)
        solve_recursive(arr,q+1,r)
            
def partition(arr,p,r):
    x = arr[r]
    i = p - 1
    for j in range(p,r):
        if(arr[j] <= x):
            i = i + 1
            arr[i],arr[j] = arr[j],arr[i]         
    arr[i+1],arr[r] = arr[r],arr[i+1]
    return i+1

def quicksort_m2(arr):
    p = 0
    r = len(arr) - 1
    solve_tail_recursive(arr,p,r)
    
def solve_tail_recursive(arr,p,r):
    while(p<r):
        q = partition(arr,p,r)
        solve_tail_recursive(arr,p,q-1)
        p += q+1
        
        
        
def main():
    arr = [2,4,3,6,5,8,6,7,1,9,14,32,30,23,87,43]
    print("before sort :", arr)
    quicksort(arr)
    print("sorted :",arr)
   
if __name__ == "__main__" :
    main()