File size: 2,544 Bytes
69b3ab8 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 | class PriorityQueue:
def __init__(self):
self.data = []
def parent(self, j):
return (j - 1) // 2
def left(self, j):
return 2 * j + 1
def right(self, j):
return 2 * j + 2
def swap(self, i, j):
self.data[i], self.data[j] = self.data[j], self.data[i]
# Heapify Up
def upheap(self, j):
while j > 0 and self.data[j][0] < self.data[self.parent(j)][0]:
self.swap(j, self.parent(j))
j = self.parent(j)
#Heapify Down
def downheap(self, j):
n = len(self.data)
while self.left(j) < n:
small = self.left(j)
r = self.right(j)
if r < n and self.data[r][0] < self.data[small][0]:
small = r
if self.data[j][0] <= self.data[small][0]:
break
self.swap(j, small)
j = small
def add(self, key, value):
self.data.append((key, value))
self.upheap(len(self.data) - 1)
def minimum(self):
if not self.data:
return "Priority Queue is Empty"
return self.data[0]
def remove_min(self):
self.swap(0, len(self.data) - 1)
item = self.data.pop()
if self.data:
self.downheap(0)
return item
# Main Program
pq = PriorityQueue()
while True:
print("\nHeaps Using Priority Queues")
print("Menu")
print("1 - Insertion")
print("2 - Remove the Highest Priority")
print("3 - Display Heap")
print("4 - Exit")
choice = int(input("Enter your choice: "))
if choice == 1:
# Insert loop
while True:
key = int(input("Enter priority key: "))
value = input("Enter value: ")
pq.add(key, value)
print("Element inserted successfully.")
cont = input("Do you want to insert more? (y/n): ").lower()
if cont != 'y':
break
elif choice == 2:
if not pq.data:
print("Priority Queue is Empty")
else:
print("Removed the Highest Priority element:", pq.remove_min())
elif choice == 3:
if not pq.data:
print("Priority Queue is Empty")
else:
print("Current Heap:", pq.data)
elif choice == 4:
print("Program Exited")
break
else:
print("Invalid choice. Try again.") |