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Can queue be implemented using stack?
A queue can be implemented using two stacks. Method 1 (By making enQueue operation costly) This method makes sure that oldest entered element is always at the top of stack 1, so that deQueue operation just pops from stack1. To put the element at top of stack1, stack2 is used.
What is a stack and queue?
Stack is a container of objects that are inserted and removed according to the last-in first-out (LIFO) principle. Queue is a container of objects (a linear collection) that are inserted and removed according to the first-in first-out (FIFO) principle.
How do you create a queue using two stacks?
The following algorithm will implement a queue using two stacks. (1) When calling the enqueue method, simply push the elements into the stack 1. (2) If the dequeue method is called, push all the elements from stack 1 into stack 2, which reverses the order of the elements. Now pop from stack 2.
How do I create a queue stack?
1. Making the Enqueue operation costly
- If the queue is empty(means S1 is empty), directly push the first element onto the stack S1 .
- If the queue is not empty, move all the elements present in the first stack( S1 ) to the second stack( S2 ), one by one.
How do you implement queue?
Queue can be implemented using an Array, Stack or Linked List. The easiest way of implementing a queue is by using an Array. Initially the head(FRONT) and the tail(REAR) of the queue points at the first index of the array (starting the index of array from 0 ).
How many queue are required to implement a stack?
Two Queues
Implement Stack Using Two Queues.
What is the principle of stack?
A stack works on the principle of Last In – First Out (LIFO) since removing a plate other than the top one on the stack is not very easy without first removing those plates above it in the stack.
Why is queue used?
Queue is used when things don’t have to be processed immediately, but have to be processed in First In First Out order like Breadth First Search. This property of Queue makes it also useful in following kind of scenarios. 1) When a resource is shared among multiple consumers.
How many stocks are needed to implement a queue?
two stacks
Explanation: A queue can be implemented using two stacks. See following for implementation.