Create priority.py

Author: satriii

Queues/Priority Queue/priority.py

@@ -0,0 +1,60 @@
+# To heapify
+def heapify(array, num, x):
+    # Find the largest among root, left child and right child
+    max = x
+    left = 2 * x + 1
+    right = 2 * x + 2
+
+    if left < num and array[x] < array[left]:
+        max = left
+
+    if right < num and array[max] < array[right]:
+        max = right
+
+    # If root is not largest, swap and continue heapifying
+    if max != x:
+        array[x], array[max] = array[max], array[x]
+        heapify(array, num, max)
+
+
+# To insert an element
+def insert(nums, next):
+    s = len(nums)
+    if s == 0:
+        nums.append(next)
+    else:
+        nums.append(next)
+        for i in range((s // 2) - 1, -1, -1):
+            heapify(nums, s, i)
+
+
+# To delete an element
+def delete(nums, n):
+    s = len(nums)
+    i = 0
+    for i in range(0, s):
+        if n == nums[i]:
+            break
+
+    nums[i], nums[s - 1] = nums[s - 1], nums[i]
+
+    nums.remove(s - 1)
+
+    for i in range((len(nums) // 2) - 1, -1, -1):
+        heapify(nums, len(nums), i)
+
+
+array = []
+
+insert(array, 1)
+insert(array, 4)
+insert(array, 2)
+insert(array, 7)
+insert(array, 8)
+insert(array, 5)
+insert(array, 6)
+
+print("Max-Heap array: " + str(array))
+
+delete(array, 6)
+print("After deletion: " + str(array))