My software development journey
Given a set of numbers and a target value, we have to find if there is any subset whose sum is equal to the target value. For example let the array be {10, 34, 19, 27, 58, 45} and the target sum is 56, we have a subset {10,19,27} with the given sum. We don’t…
In this post I introduce you to a competitive programming problem called Jolly jumpers. This problem is available on UVa online judge on this link. UVa site is one of the first online judge websites which listed programming problems from different competitions like ACM ICPC and IOI and allowed users to solve and submit their…
Given an array of positive and negative numbers, how do we write a program to check if it has three elements with sum 0. For example, the array {-31, 19, -6, -45, 12, -8, 3, -77, 56, 29} contains {-31,12,19} with sum zero. One obvious solution is to examine each possible triplet of the array…
Given a row wise and column wise sorted two dimensional array or matrix. How to search for an element efficiently? Example of the array can be int[][] matrix = { {1,3,5,7,9}, {10,12,14,16,18}, {19,21,23,25,27}, {28,30,32,34,36}, {37,39,41,43,45} }; This can be done using the following algorithm. We start our search with the top right element. If it…
Given array of elements we have to write a program to print the biggest element to it’s right for each of the elements in the given array. For example let us consider the array {3, 9, 2, 4, 6, 1}. The output for this array should be {9, 6, 6, 6, 1, -1}. As a…
Given an array of 2n numbers of the following format {a1, a2, a3,…an, b1, b2, b3, …bn} We have to write a program to transform this into the following format. {a1, b1, a2, b2, a3, b3, …, an, bn} This can be done using the following algorithm. We iterate over the array for (n-1) times. In…
Given a sorted array and a value, we have to find the closest value (with least difference). For example let the input array be {-2, 4, 7, 11, 17} and the input number is 10, the output should be 11. This problem is actually a variation of binary search where in we have to find…
Given an array of elements which contains some zeros in between, we have to write a program to move all zeros to the end without disturbing the original order of the elements.For example if the input is {0, 6, 2, 0, 0, 3, 1, 0, 4, 5, 0}, the output should be {6, 2, 3,…
Given a large file containing many lines of text, How do we write an efficient program to print last k lines from that file. One obvious approach is to read the entire file first to find the number of lines (n). In the second iteration skip first (n-k) lines, and print the remaining k lines. …
Given an array of N elements, the majority element is defined as the one which occurs more than N/2 times. One simple approach is to find the mode (which appears for most number of times) and check if its frequency is greater than N/2. Three strategies for finding the mode are discussed in my previous…