Find all unique pairs of maximum and second maximum elements over all sub-arrays in O(NlogN)
Let represent the ordered pair of the second maximum and the maximum element of an array respectively. We need to find all such unique pairs… Read More »
Category Archives: Stack
Python | Stack using Doubly Linked List
A stack is a collection of objects that are inserted and removed using Last in First out Principle(LIFO). User can insert elements into the stack,… Read More »
InfyTQ 2019 : Find the position from where the parenthesis is not balanced
Given a string str consisting of parenthesis from [ “(” , “)” , “{” , “}” , “[” , “]” ]. If the String is… Read More »
Introduction to Data Structures | 10 most commonly used Data Structures
A data structure is a particular way of organizing data in a computer so that it can be used effectively. The idea is to reduce… Read More »
Implementing Forward Iterator in BST
Given a Binary search tree, the task is to implement forward iterator on it with the following functions. curr(): returns the pointer to current element.… Read More »
Nodes from given two BSTs with sum equal to X
Given two Binary search trees and an integer X, the task is to find a pair of nodes, one belonging to the first BST and… Read More »
Triplet with a given sum in BST | Set 2
Given a binary search tree, and an integer X, the task is to find if there exists a triplet with sum X. Print Yes or… Read More »
Design a stack which can give maximum frequency element
Given N elements and the task is to implement a stack which removes and returns the maximum frequency element on every pop operation. If there’s… Read More »
Reverse the Sentence using Stack
Given a string str consisting of a sentence, the task is to reverse the entire sentence word by word. Examples: Input: str = “geeks for… Read More »
Analyzing BufferOverflow with GDB
Pre-requisite: GDB (Step by Step Introduction) A BufferOverflow often occurs when the content inside the defined variable is copied to another variable without doing Bound… Read More »
Check if the two given stacks are same
Given two Stacks, the task is to check if the given stacks are same or not. Two stacks are said to be same if they… Read More »
Delete all even elements from a stack
Given a stack with n elements, the task is to remove all the elements of the stack without affecting the order of elements. Examples: Input… Read More »
Iterative Postorder traversal | Set 3
We have seen different ways of performing postorder traversal on Binary Trees. Post Order Traversal. Iterative Postorder Traversal using Two Stacks. Iterative Postorder Traversal using… Read More »
Sliding Window Maximum (Maximum of all subarrays of size k) using stack in O(n) time
Give an array arr[] of N integers and another integer k ≤ N. The task is to find the maximum element of every sub-array of… Read More »
Find maximum in stack in O(1) without using additional stack
The task is to design a stack which can get the maximum value in the stack in O(1) time without using an additional stack. Examples:… Read More »
