def move_zeros_to_end(arr):
j = 0
ln = len(arr)
for i in range(ln):
if arr[i] != 0:
arr[j] = arr[i]
j+=1
while j < ln:
arr[j] = 0
j += 1
arr = [0, 3, 4, 0, 6, 0, 0, 8, 9, 0]
move_zeros_to_end(arr)
print(arr)
'''
run:
[3, 4, 6, 8, 9, 0, 0, 0, 0, 0]
'''