Problem p02928 (python)

Fixed submission:
import sys
input = sys.stdin.readline

def bubble_sort(A):
    flag = 1  # if non-sorted element exist on side
    counter = 0
    while flag:
        flag = 0
        for i in range(1, len(A))[::-1]:
            if A[i] < A[i - 1]:
                counter += 1
                A[i], A[i - 1] = A[i - 1], A[i]
                flag = 1
    return (A,counter)


def main():
    _,k = [int(i) for i in input().strip().split()]
    l = [int(i) for i in input().strip().split()]
    _sorted, inner = bubble_sort(l)
    _, outer = bubble_sort(_sorted + _sorted)
    
    print((inner * k + (k * (k - 1) // 2) * outer) % (10 ** 9 + 7))
    
if __name__ == "__main__":
    main()

Buggy submission (verdict: Runtime Error):
import numpy as np

def mergeSort(arr, n): 
    # A temp_arr is created to store 
    # sorted array in merge function 
    temp_arr = [0]*n 
    return _mergeSort(arr, temp_arr, 0, n-1) 
  
# This Function will use MergeSort to count inversions 
  
def _mergeSort(arr, temp_arr, left, right): 
  
    # A variable inv_count is used to store 
    # inversion counts in each recursive call 
  
    inv_count = 0
  
    # We will make a recursive call if and only if 
    # we have more than one elements 
  
    if left < right: 
  
        # mid is calculated to divide the array into two subarrays 
        # Floor division is must in case of python 
  
        mid = (left + right)//2
  
        # It will calculate inversion counts in the left subarray 
  
        inv_count = _mergeSort(arr, temp_arr, left, mid) 
  
        # It will calculate inversion counts in right subarray 
  
        inv_count += _mergeSort(arr, temp_arr, mid + 1, right) 
  
        # It will merge two subarrays in a sorted subarray 
  
        inv_count += merge(arr, temp_arr, left, mid, right) 
    return inv_count 
  
# This function will merge two subarrays in a single sorted subarray 
def merge(arr, temp_arr, left, mid, right): 
    i = left     # Starting index of left subarray 
    j = mid + 1 # Starting index of right subarray 
    k = left     # Starting index of to be sorted subarray 
    inv_count = 0
  
    # Conditions are checked to make sure that i and j don't exceed their 
    # subarray limits. 
  
    while i <= mid and j <= right: 
  
        # There will be no inversion if arr[i] <= arr[j] 
  
        if arr[i] <= arr[j]: 
            temp_arr[k] = arr[i] 
            k += 1
            i += 1
        else: 
            # Inversion will occur. 
            temp_arr[k] = arr[j] 
            inv_count += (mid-i + 1) 
            k += 1
            j += 1
  
    # Copy the remaining elements of left subarray into temporary array 
    while i <= mid: 
        temp_arr[k] = arr[i] 
        k += 1
        i += 1
  
    # Copy the remaining elements of right subarray into temporary array 
    while j <= right: 
        temp_arr[k] = arr[j] 
        k += 1
        j += 1
  
    # Copy the sorted subarray into Original array 
    for loop_var in range(left, right + 1): 
        arr[loop_var] = temp_arr[loop_var] 
          
    return inv_count 
  
# Driver Code 
# Given array is 



print("Number of inversions are", result) 
N,K = list(map(int,input().split()))
l = list(map(int,input().split()))
L = np.array(l)
for _ in range(K-1):
    L = np.append(L,l)

arr = L
n = len(L) 
c = mergeSort(arr, n) 


print(c%((10**7)+7))