My software development journey
Given an array of numbers A[N], how do we arrange them in the following order. A[0] <= A[1] >= A[2] <= A[3]…A[N-1] For example consider the array A =[6, 9, 36, 24, 42] The answer can be [6, 36, 9, 42, 24]. There can be multiple answers also like [6, 42, 9, 36, 24]. We…
Given an array of numbers, how do we search for a given number? For example, given an array [6, 50, 24, 36, 42], the number 36 is present at the index 3 starting with 0. The number 17 is not present any where. The simplest algorithm to solve this problem is to check each element…
Given two arrays of numbers, how to check if the first sequence is a sub sequence of second sequence.For example [3, 7, 11] is a sub-sequence of [9, 3, 1, 7, 5, 11]where as [4, 8, 9] is not a sub-sequence of [6, 4, 9, 2, 8]The algorithm here is simple. Let us assume two…
Given an array of numbers ( minimum length 3), find an index such that all the elements to the left of it are less than or equal, and all the elements to the right of it are greater than it. For example in the array [1, 2, 3], the pivot element is 2, as all…
Given a rectangle of some length and width, How do you divide them into minimum number of squares? This is a problem from Codechef.For example give a rectangle of size 2 x 4, we can make them into two squares of 2 x 2.Similarly a rectangle of size 3 x 7, can only be divided…
Given a permutation of numbers from 1 to N, We can represent it in two ways. For example, let us consider a permutation from 1 to 5 P = [2 4 1 5 3] This representation directly indicates the position of each number. i.e 2 is first, 4 is second and so on. Alternatively, this…
Given an array of numbers A, which might contain duplicate elements, How do we find if there are two elements A[i], A[j] such that i, j are distinct and the difference between them is at most k? Look at the following examples.1. A = [9, 5, 6, 9, 3, 0, 1], K =3The answer is…
Given a binary tree, how to convert it to it’s mirror image?For example consider the following binary tree and it’s mirror image. Here simply, the left and right sub trees of each node are inverted. So we have to simply invert the given binary tree. It is a simple implementation problem. Using recursion we can…
Given an array of elements, how do we find the XOR of each sub-array and XOR of those results? For example let us consider the array [1, 2, 3], all possible sub-arrays are XOR[1] = 1XOR[1, 2] = 1 ^ 2 = 3XOR[1, 2, 3] = 1 ^ 2 ^ 3 = 0XOR[2] = 2XOR[2,…
Given a string, We have to find out by removing which character, it becomes a palindrome.For example consider the string “racercar”, the character ‘r’ at index 4 should be removed to become a palindrome.The approach here is simple. Start from both ends of the string and compare both characters. If they are equal, we increment…