We are given queue data structure, the task is to implement stack using only given queue data structure.
We have discussed a solution that uses two queues. In this article, a new solution is discussed that uses only one queue. This solution assumes that we can find size of queue at any point. The idea is to keep newly inserted element always at rear of queue, keeping order of previous elements same. Below are complete steps.
// x is the element to be pushed and s is stack push(s, x) 1) Let size of q be s. 1) Enqueue x to q 2) One by one Dequeue s items from queue and enqueue them. // Removes an item from stack pop(s) 1) Dequeue an item from q
Below is implementation of the idea.
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