Sliding Window Deque Moves

Problem

Process every size-k window with a monotonic deque of indices and count its operations. back_pops counts removals from the back while the back value is <= the incoming value; front_pops counts removals from the front when the front index has left the window. Return [back_pops, front_pops], or [] when k is not positive or larger than the array.

Hint

Values leave the back when a larger newcomer arrives and the front when their index is out of range.

Test cases

case 1

in: [[1,3,2,5,4],3]

expected: [3,0]

case 2

in: [[5,5,5,5],2]

expected: [3,0]

case 3

in: [[1],1]

expected: [0,0]

case 4

in: [[1,2],3]

expected: []

Starter codePython

def sliding_window_deque_moves(nums, k):
    # Your code here
    pass

4 test cases · run your code against them in the editor