Priority Queue
Priority Queues are abstract data structures where each data/value in the queue has a certain priority. For example, In airlines, baggage with the title “Business” or “First-class” arrives earlier than the rest. Priority Queue is an extension of the queue with the following properties.
- An element with high priority is dequeued before an element with low priority.
- If two elements have the same priority, they are served according to their order in the queue.
# A simple implementation of Priority Queue
# using Queue.
class PriorityQueue(object):
def __init__(self):
self.queue = []
def __str__(self):
return ' '.join([str(i) for i in self.queue])
# for checking if the queue is empty
def isEmpty(self):
return len(self.queue) == 0
# for inserting an element in the queue
def insert(self, data):
self.queue.append(data)
# for popping an element based on Priority
def delete(self):
try:
max = 0
for i in range(len(self.queue)):
if self.queue[i] > self.queue[max]:
max = i
item = self.queue[max]
del self.queue[max]
return item
except IndexError:
print()
exit()
if __name__ == '__main__':
myQueue = PriorityQueue()
myQueue.insert(12)
myQueue.insert(1)
myQueue.insert(14)
myQueue.insert(7)
print(myQueue)
while not myQueue.isEmpty():
print(myQueue.delete())
Output
12 1 14 7 14 12 7 1
Learn DSA with Python | Python Data Structures and Algorithms
This tutorial is a beginner-friendly guide for learning data structures and algorithms using Python. In this article, we will discuss the in-built data structures such as lists, tuples, dictionaries, etc, and some user-defined data structures such as linked lists, trees, graphs, etc, and traversal as well as searching and sorting algorithms with the help of good and well-explained examples and practice questions.
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