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As we know that the gray code is a binary numeral system where two successive values differ in only one bit. Suppose we have a non-negative integer n representing the total number of bits in the code. We have to print the sequence of gray code. A gray code sequence must begin with 0. So if the input is 2, then the result will be [0, 1, 3, 2], this is because gray of 0 is 00, gray of 1 is 01, gray of 2 is 11, and gray of 3 is 10.To solve this, we will follow these steps ... Read More
Suppose we have a linked list and a value x. We have to make partitions. The partition it such that all nodes less than x comes before the nodes that are greater than or equal to x. We should preserve the original relative order of the nodes in each of these two partitions. So if the list is like [1, 4, 3, 2, 5, 2] and x = 3, then the output will be [1, 2, 2, 4, 3, 5]To solve this, we will follow these steps −Make dummy nodes d1 and d2, and initialize them with -1, create two ... Read More
JShell is an interactive command-line tool used to implement simple statements like expressions, classes, methods, fields, interfaces, and etc. String class is part of the built-in java.lang package and provides several methods for common text processing.1) String Utility: String provides several built-in utility methods. The methods like indexOf(), lastIndexOf(), startsWith(), endsWith(), isEmpty(), equals(), equalsIgnoreCase() are that part of string utility.In the below code snippet, we have implemented the string utility methods in the JShell tool.Snippet-1jshell> String str = "JShell is a new feature in Java9"; str ==> "JShell is a new feature in Java9" jshell> str.indexOf("new") $4 ==> 12 ... Read More
Suppose we have two integers n and k. We have to find all possible combinations of k numbers out of 1 ... n. So if n = 4 and k = 2, then the combinations will be [[1, 2], [1, 3], [1, 4], [2, 3], [2, 4], [3, 4]]To solve this, we will follow these steps −We will use recursive function to solve this. the function solve() is taking n, k, temp array and start. The start is initially 1. This will act likeif size of temp array = k, then insert temp into res array, and returnfor i := ... Read More
Suppose we have an array with n objects. These are colored red, white, or blue, sort them in place so that the objects of the same color are adjacent. So with the colors in the order red, white and blue. Here, we will use the numbers like 0, 1, and 2 to represent the color red, white, and blue respectively. So if the array is like [2,0,2,1,1,0], then the output will be [0,0,1,1,2,2]To solve this, we will follow these steps −set low := 0, mid := 0 and high := length of array – 1while mid
Suppose we have a matrix and we have to print the matrix elements in a spiral way. At first starting from the first row, print the whole content and then follow the last column to print, then the last row, and so on, thus it prints the elements in a spiral fashion. So if the matrix is like −123456789101112131415161718Then the output will be like [1 2 3 4 5 6 12 18 17 16 15 14 13 7 8 9 10 11 15 16]To solve this, we will follow these steps −currRow := 0 and currCol := 0while currRow and ... Read More
Suppose we have two inputs x and n. x is a number in range -100.0 to 100.0, and n is a 32-bit signed integer. We have to find x to the power n without using library functions.So if the given inputs are x = 12.1, n = -2, then output will be 0.00683To solve this, we will follow these steps −power := |n| and res := 1.0while power is not 0if last bit of power is 1, then res := res * xx := x * xif n < 0return 1 / resreturn resExample(Python)Let us see the following implementation to ... Read More
Suppose we have one 2D matrix, that is representing one image. We have to rotate this image to 90 degrees clockwise. So if the image is like157963213Then the output will be291165337To solve this, we will follow these steps −Consider temp_mat = [], col := length of matrix – 1for col in range 0 to length of matrixtemp := []for row in range length of matrix – 1 down to -1add matrix[row, col] in tempadd temp into temp_matfor i in range 0 to length of matrixfor j in range 0 to length of matrixmatrix[i, j] := temp_mat[i, j]Example(Python)Let us see the ... Read More
Suppose we have a collection of distinct integers; we have to find all possible permutations. Now if the array stores the duplicate elements, then ignore that state which is looking similar. So if the array is like [1, 1, 3], then the result will be [[1, 1, 3], [1, 3, 1], [3, 1, 1]]To solve this, we will follow these steps −We will use the recursive approach, this will make the list, index. Index is initially 0if index = size of the list then insert list into res array, and returnfor i in range index to length of given list ... Read More
Suppose we have one 9x9 Sudoku board. We have to check whether that is valid or now. Only the filled cells need to be validated according to the following rules −Each row must contain the digits from 1-9 without repetition.Each column must contain the digits from 1-9 without repetition.Each of the 9 (3x3) sub-boxes of the grid must contain the digits from 1-9 without repetition.Suppose the Sudoku grid is like −537619598686348317266284195879This is valid.To solve this, we will follow these steps −for i in range 0 to 8create some empty dictionary called row, col and block, row_cube := 3 * (i ... Read More