Given a string, find its first non-repeating character

Given a string, find the first non-repeating character in it. For example, if the input string is “GeeksforGeeks”, then output should be ‘f&#x2...

Queue Recursion Stack

Level order traversal in spiral form

Write a function to print spiral order traversal of a tree. For below tree, function should print 1, 2, 3, 4, 5, 6, 7. Recommended: Please solve it on “PRAC...

Tree Amazon Kritikal Solutions

Boundary Traversal of binary tree

Given a binary tree, print boundary nodes of the binary tree Anti-Clockwise starting from the root. For example, boundary traversal of the following tree is “2...

Tree Accolite Amazon

Lowest Common Ancestor in a Binary Tree Set 1

Given a binary tree (not a binary search tree) and two values say n1 and n2, write a program to find the least common ancestor. Following is definition of LCA from W...

Hash Linked List Python

Find the first non-repeating character from a stream of characters

Given a stream of characters, find the first non-repeating character from stream. You need to tell the first non-repeating character in O(1) time at any moment. If we...

Arrays Searching Amazon

Find the Missing Number

You are given a list of n-1 integers and these integers are in the range of 1 to n. There are no duplicates in list. One of the integers is missing in the list. Wri...

Arrays Payu Payu

Leaders in an array

Write a program to print all the LEADERS in the array. An element is leader if it is greater than all the elements to its right side. And the rightmost element is al...

Dynamic Programming Fibonacci Payu

Count possible ways to construct buildings

Given an input number of sections and each section has 2 plots on either sides of the road. Find all possible ways to construct buildings in the plots such that there...

Pattern Searching Strings MAQ Software

Naive algorithm for Pattern Searching

Given a text txt[0..n-1] and a pattern pat[0..m-1], write a function search(char pat[], char txt[]) that prints all occurrences of pat[] in txt[]. You may assume that...

Pattern Searching Strings Accolite

KMP Algorithm for Pattern Searching

Given a text txt[0..n-1] and a pattern pat[0..m-1], write a function search(char pat[], char txt[]) that prints all occurrences of pat[] in txt[]. You may assume tha...