Create Deque.py

Dequeue array in python

Author: sultanarif-p

data_structures/arrays/Deque.py

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+# Find maximum of every window of size k
+from collections import deque
+
+arr = [1,3,-1,-3,5,3,6,7]
+k = 3
+dq = deque()
+res = []
+
+for i, val in enumerate(arr):
+    while dq and dq[0] <= i-k:
+        dq.popleft()  # remove out-of-window indices
+    while dq and arr[dq[-1]] < val:
+        dq.pop()  # remove smaller elements
+    dq.append(i)
+    if i >= k-1:
+        res.append(arr[dq[0]])
+
+print(res)  # [3, 3, 5, 5, 6, 7]