How to implement a queue using two stacks. In this tutorial, I am going to discuss how to implement a first in first out (FIFO) queue using only two stacks.
In this problem, we are going to implement following methods of QueueUsingStack class:
void push(int x) – Insert an element x.
int pop() – Removes the element (In FIFO order).
int peek() – Returns the element which is present at the front of the queue.
boolean empty() – Returns true if no element is present else false.
For example –
Write a php program to print prime numbers between 1 to N. In this tutorial, we are going to use Sieve of Eratosthenes algorithm to print prime numbers between 1 to N.
Write a java program to find common elements in three sorted arrays.
Given three sorted arrays, write a code to print intersection of three sorted arrays.
For example –
arr1 = {1, 5, 10, 20, 40, 80};
arr2 = {6, 7, 20, 80, 100};
arr3 = {3, 4, 15, 20, 30, 70, 80, 120};
Output : {20, 80}
20 and 80 are the common elements in 3 arrays. These two elements are the intersection of 3 sorted arrays.