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. 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
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). So we have to find how many possible unique paths are there? For example if m = 3 and n = 2, then the grid will be like below −RoboENDThe output will be 3, So there are total 3 different ways to reach from start ... Read More
Suppose we have a linked list. We have to rotate the list to the right k places. The value of k is not negative. So if the list is like [1, 23, 4, 5, NULL], and k = 2, then the output will be [4, 5, 1, 2, 3, NULL]Let us see the steps −If the list is empty, then return nulllen := 1create one node called tail := headwhile next of tail is not nullincrease len by 1tail := next of tailnext of tail := headk := k mod lennewHead := nullfor i := 0 to len – ktail ... Read More
Suppose the set is like [1, 2, 3, ..., n], contains a total of n! unique permutations. By listing and labeling all of the permutations in order, we get these sequence for n = 3: ["123", "132", "213", "231", "312", "321"] So if n and k are given, then return the kth permutation sequence. The n will be between 1 to 9 (inclusive) and k will be between 1 to n! (inclusive). For example if n = 3.Let us see the steps −ans := empty string, define array called candidates of size nfor i in range 0 to n – ... Read More
Suppose we have a positive integer n, we have to generate a square matrix with n2 elements in spiral order. So if n = 5, then the matrix will be −12341213145111615610987Let us see the steps −set (row1, col1) := (0, 0) and (row2, col2) := (n, n), and create one matrix called res, then fill it with 0s, and set num := 1while num n2, then breakfor i in range row1 + 1 to row2, res[i, col2-1] = num, incase num by 1if num > n2, then breakfor i in range col2 – 2 down to col1 – 1, ... Read More