## DEV Community

Abhishek Chaudhary

Posted on

# Sliding Window Maximum

You are given an array of integers `nums`, there is a sliding window of size `k` which is moving from the very left of the array to the very right. You can only see the `k` numbers in the window. Each time the sliding window moves right by one position.

Return the max sliding window.

Example 1:

Input: nums = [1,3,-1,-3,5,3,6,7], k = 3
Output: [3,3,5,5,6,7]
Explanation:
Window position Max

[1 3 -1] -3 5 3 6 7 3
1 [3 -1 -3] 5 3 6 7 3
1 3 [-1 -3 5] 3 6 7 ** 5**
1 3 -1 [-3 5 3] 6 7 5
1 3 -1 -3 [5 3 6] 7 6
1 3 -1 -3 5 [3 6 7] 7

Example 2:

Input: nums = [1], k = 1
Output: [1]

Constraints:

• `1 <= nums.length <= 105`
• `-104 <= nums[i] <= 104`
• `1 <= k <= nums.length`

SOLUTION:

``````import heapq

class Solution:
def maxSlidingWindow(self, nums: List[int], k: int) -> List[int]:
n = len(nums)
maxes = []
deleted = {}
window = [-num for num in nums[:k]]
heapq.heapify(window)
maxes.append(-window[0])
for i in range(0, n - k):
heapq.heappush(window, -nums[i + k])
deleted[-nums[i]] = deleted.get(-nums[i], 0) + 1
curr = window[0]
while curr in deleted:
heapq.heappop(window)
deleted[curr] -= 1
if deleted[curr] == 0:
del deleted[curr]
curr = window[0]
maxes.append(-curr)
return maxes
``````