Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Suppose we have a set of numbers; we have to generate all possible subsets of that set. This is also known as power set. We have to keep in mind that the elements may be duplicate. So if the set is like [1, 2, 2], then the power set will be [[], [1], [2], [1, 2], [2, 2], [1, 2, 2]]Let us see the steps −Define one array res and another set called xWe will solve this using recursive approach. So if the recursive method name is called solve(), and this takes index, one temporary array, and the array of ... Read More
Suppose we have a list of some elements. We have to remove all elements that have occurred more than once. So only the distinct elements will remain in the list. So if the list is like [1, 1, 1, 2, 2, 3, 5, 6, 6, 7, 8], then the output will be [3, 5, 7, 8], all other elements are present more than once.Let us see the steps −Create a dummy node with value -1, prev := NULL, dummyPtr := dummywhile head is not nullif next of head is present or the value of head is not same as the ... Read More
Consider we have an array sorted in ascending order. That is rotated at some pivot unknown to us beforehand. For example, if the array is like [0, 0, 1, 2, 2, 5, 6], this might become [2, 5, 6, 0, 0, 1, 2]. We have a target value to search. If that is found in the array, then return true, otherwise return false. So if the array is like [2, 5, 6, 0, 0, 1, 2], and target is 0, then the output will be 0Let us see the steps −low := 0 and high := size of arraywhile low ... Read More
Suppose we have a sorted array nums, we have to remove the duplicates in-place such that duplicates elements will appear at most twice and return the new length. To do this task we cannot take extra space. We have to solve this with O(1) amount of space. For example, if the array is like [0,0,0,1,1,1,1,2,3,3], then the output will be [0,0,1,1,2,3,3], its length is 7Let us see the steps −len := 2 and n := size of arrayif n
Suppose we have a set of numbers; we have to generate all possible subsets of that set. This is also known as power set. So if the set is like [1, 2, 3], then the power set will be [[], [1], [2], [3], [1, 2], [1, 3], [2, 3], [1, 2, 3]]Let us see the steps −We will solve this using recursive approach. So if the recursive method name is called solve(), and this takes the set of numbers (nums), temporary set (temp), res and indexThe solve() function will work like below −if index = length of nums, then create ... Read More
Suppose we have write an efficient algorithm to searches for a value in one m x n matrix. This matrix has some properties like below −Each row is sorted from left to rightThe first number of each row is greater than the last integer of the previous row.So if the matrix is like −1357101116202330345053627898And if the target value is 16, then the output will be True.Let us see the steps −n := number of rows, if n is 0, then return false, m := number of columns, if m = 0, then return falselow := 0 and high := n ... Read More
Consider we have a matrix, in that matrix if one element is 0, then make the entire row and column of that matrix to 0. The conversion will be in-place. So if the matrix is −101111111Then the output will be −000101101Let us see the steps −n := number of rows, m := number of columns, set flag := falseif mat[0, 0] = 0, then set flag := trueset row := false, and col := falsefor i in range 1 to nif mat[i, 0] = 0, then set col := True and break the loopfor i in range 1 to mif ... Read More
Suppose we have an absolute path for a file (Like Unix File system), we have to simplify it. Or in other words, we have to convert it to the canonical path. In the UNIX-style file system, a period ‘.’ refers to the current directory. And a double period ‘..’ moves the directory up a level (Parent directory). The properties of canonical paths are as follows.Path must always begin with a slash /There must be only a single slash / between two directory names.Last directory name (if it exists) must not end with a trailing /.Canonical path must be the shortest ... Read More
Suppose we have a m x n matrix filled with non-negative integers, find a path from top left corner to bottom right corner which minimizes the sum of all numbers along its path. Movements can only be either down or right at any point in time. So for example, if the matrix is like below131151421The output will be 7, the path will be 1, 3, 1, 1, 1, this will minimize the sumLet us see the steps −a := number of rows, b := number of columnsi := a – 1, j := b – 1while j >= 0matrix[a, j] ... Read More
Suppose there is a robot is located at the top-left corner of a n x m grid (n rows and m columns). The robot can only move either down side or right side at any point in time. The robot wants to reach the bottom-right corner of the grid (marked 'END in the diagram below).Some cell in the grid is marked, that will be considered as obstacles. So we have to find how many possible unique paths are there? For example if the grid is like [[0, 0, 0], [0, 1, 0], [0, 0, 0]], then the grid will be ... Read More