How do I check if a queue is empty?
How do I check if a queue is empty?
queue. isEmpty() returns true if the queue is empty; otherwise, it returns false .
What is the value of front when queue is empty?
Queue is said to be empty when the value of front is at -1 or the value of front becomes greater than rear (front > rear).
When the queue is empty front and rear?
In the beginning when the queue is empty, FRONT and REAR point to 0 index in the array. REAR represents insertion at the REAR index. FRONT represents deletion from the FRONT index.
What is the front of a queue?
Also in other words we can state that front() directly refers to the element which is oldest in a queue container. Like in the above given figure, head i.e. 1 is the first element which has been entered in the queue and tail i.e. -4 is the last or the most recent element which is entered in the queue.
Why do we need is empty in a queue?
isEmpty: Check if the queue is empty To prevent performing operations on an empty queue, the programmer is required to internally maintain the size of the queue which will be updated during enqueue and deque operations accordingly. isEmpty() conventionally returns a boolean value: True if size is 0, else False.
How do I check if a queue is empty in Python?
Python Data Structure: Find whether a queue is empty or not
- Sample Solution:
- Python Code: import queue p = queue.Queue() q = queue.Queue() for x in range(4): q.put(x) print(p.empty()) print(q.empty())
- Flowchart:
- Python Code Editor:
- Contribute your code and comments through Disqus.
What will be the result if both front and rear contain null?
If front and rear both are NULL, it indicates that the queue is empty.
How an empty queue is distinguished from a full queue?
Basic Operations peek() − Gets the element at the front of the queue without removing it. isfull() − Checks if the queue is full. isempty() − Checks if the queue is empty.
What will be front and rear If indexing of queue starts from 0?
If the MAX_SIZE is the size of the array used in the implementation of circular queue, array index start with 0, front point to the first element in the queue, and rear point to the last element in the queue.
How do you access the front element of a queue?
C++ Queue Library – front() Function The C++ function std::queue::front() returns a reference to the first element of the queue. This element will be removed after performing pop operation on queue. This member function effectively calls the front member function of underlying container.
What is front function?
C++ Queue front() function returns the value of the front element of the queue. The first element is the oldest element or the element which was initially added to the queue. The function is used to return that element.
Is Empty operation in queue?
isNull() Operation Step 1: Check if the rear and front are pointing to null memory space, i.e., -1. Step 2: If they are pointing to -1, return “Queue is empty.” Step 3: If they are not equal, return “Queue is not empty.”
