Minimum number of queues to implement stack is ___________Select one:a.3.b.4.c.1.d.2.

To determine the minimum number of queues required to implement a stack, let's analyze the operations of a stack and how they can be simulated using queues.

A stack supports two primary operations:

1. Push: Add an element to the top of the stack.
2. Pop: Remove the element from the top of the stack.

Queues, on the other hand, operate on a First-In-First-Out (FIFO) principle, whereas stacks operate on a Last-In-First-Out (LIFO) principle. To simulate the LIFO behavior of a stack using FIFO queues, we need to carefully manage the order of elements.

Step-by-Step Analysis:

1. Using One Queue:

   • It is possible to implement a stack using a single queue by manipulating the order of elements during the push operation.
   • When pushing an element, enqueue it to the queue, and then dequeue all other elements and enqueue them back to the queue. This ensures that the most recently added element is always at the front of the queue, simulating the LIFO behavior of a stack.

2. Using Two Queues:

   • Another approach is to use two queues to manage the stack operations.
   • For the push operation, enqueue the element to the first queue.
   • For the pop operation, transfer all elements except the last one from the first queue to the second queue, then dequeue the last element from the first queue (which is the top of the stack), and finally swap the roles of the two queues.

Conclusion:

Both methods are valid, but the first method demonstrates that it is possible to implement a stack using just one queue by carefully managing the order of elements during the push operation.

Therefore, the minimum number of queues required to implement a stack is:

c. 1