Find First Unique Character From a Stream of Characters Problem Given a string A denoting a stream of lowercase alphabets. You have to make new string B. B is formed such that we have to find first non-repeating character each time a character is inserted to the stream and append it at the end to B. If no non-repeating character is found then append ’#’ at the end of B. ...
Problem You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise). Another way to ask the same problem Given an image represented by an NxN matrix, where each pixel in the image is 4 bytes, write a method to rotate the image by 90 degrees. Can you do this in place? Examples Example 1: ...
Problem Implement int sqrt(int x). OR Compute and return the square root of x. OR If x is not a perfect square, return floor(sqrt(x)) OR floor(√n) OR Given a non-negative integer x, compute and return the square root of x. Since the return type is an integer, the decimal digits are truncated, and only the integer part of the result is returned. ...
Problem Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum. Examples Example 1: Input: nums = [-2,1,-3,4,-1,2,1,-5,4] Output: 6 Explanation: [4,-1,2,1] has the largest sum = 6. ...
Problem You are climbing a staircase. It takes n steps to reach the top. Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top? OR There are n stairs, a person standing at the bottom wants to reach the top. The person can climb either 1 stair or 2 stairs at a time. Count the number of ways, the person can reach the top. ...
Problem Given the heads of two singly linked-lists headA and headB, return the node at which the two lists intersect. If the two linked lists have no intersection at all, return null. Intersection point means end of one linked list is linked with some node in another linked list and it forms a Y shape. Input: Two Linked List Output: Intersection Node or point, find Intersection Point in Two Linked List ...
Problem Given a string s, return the longest palindromic substring in s. Incase of conflict, return the substring which occurs first ( with the least starting index ). Substring of string S: S[i...j] where 0 <= i <= j < len(S) Example Example 1: Input: s = "babad" Output: "bab" Explanation: "aba" is also a valid answer. ...
Problem Given the roots of two binary trees root and subRoot, return true if there is a subtree of root with the same structure and node values of subRoot and false otherwise. A subtree of a binary tree tree is a tree that consists of a node in tree and all of this node’s descendants. The tree tree could also be considered as a subtree of itself. Examples Example 1: ...
Problem Given an m x n matrix of 0s and 1s, provide an algorithm such that if an element is 0, its entire row and column is set to 0 OR Given an m x n integer matrix matrix, if an element is 0, set its entire row and column to 0’s. You must do it in place. Follow Up: Can you do it in one pass? ...
Problem Given a circular linked list, implement an algorithm which returns node at the beginning of the loop. If there is no cycle, return null. Try solving it using constant additional space. Definition - Circular Linked List A (corrupt) linked list in which a node’s next pointer points to an earlier node, so as to make a loop in the linked list. This is extension of Linked List Cycle 1 - Detect Cycle ...