Python3 Program to Move all zeroes to end of array | Set-2 (Using single traversal)

Given an array of n numbers. The problem is to move all the 0’s to the end of the array while maintaining the order of the other elements. Only single traversal of the array is required.
Examples: 

Input : arr[]  = {1, 2, 0, 0, 0, 3, 6}
Output : 1 2 3 6 0 0 0

Input: arr[] = {0, 1, 9, 8, 4, 0, 0, 2, 7, 0, 6, 0, 9}
Output: 1 9 8 4 2 7 6 9 0 0 0 0 0

Algorithm:

moveZerosToEnd(arr, n)
    Initialize count = 0
    for i = 0 to n-1
        if (arr[i] != 0) then
            swap(arr[count++], arr[i])

Python3

# Python implementation to move all zeroes at
# the end of array

# function to move all zeroes at
# the end of array
def moveZerosToEnd (arr, n):

    # Count of non-zero elements
    count = 0;

    # Traverse the array. If arr[i] is non-zero, then
    # swap the element at index 'count' with the
    # element at index 'i'
    for i in range(0, n):
        if (arr[i] != 0):
            arr[count], arr[i] = arr[i], arr[count]
            count+=1


# function to print the array elements
def printArray(arr, n):

    for i in range(0, n):
        print(arr[i],end=" ")


# Driver program to test above
arr = [ 0, 1, 9, 8, 4, 0, 0, 2,
    7, 0, 6, 0, 9 ]
n = len(arr)

print("Original array:", end=" ")
printArray(arr, n)

moveZerosToEnd(arr, n)

print("
Modified array: ", end=" ")
printArray(arr, n)

# This code is contributed by
# Smitha Dinesh Semwal

Output:

Original array: 0 1 9 8 4 0 0 2 7 0 6 0 9 
Modified array: 1 9 8 4 2 7 6 9 0 0 0 0 0

Time Complexity: O(n). 
Auxiliary Space: O(1).

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