My software development journey
Given some text and a word. How do we find the frequency of the word?In this post we will see a Java program which finds it with just a few lines of code using regular expression matching. Java provides utilities for matching the regular expressions using java.util.regex package. In our program we utilize two of…
In selection sort, a list is sorted in the following way. Initially there will be an empty sorted list and the un-sorted list. We select the first element(According to the sort order) from the unsorted list and add it to the sorted list. We select the second element and append it to the sorted list…
Median of an array is defined as the middle element when it is sorted. The middle element is the one which divides the array into two equal halves if the array is of odd length. If the length is even, the average of two middle elements is median.For example the median of [4,3,2,5,1] is 3…
In some applications like card games, we need to shuffle an array of objects. In this post we will consider the problem of shuffling an array of numbers so that the same algorithm would be applicable for any type of arrays. We use the random number generator in this algorithm. Let us consider an array…
Given a list of numbers. How do we write a program to find the duplicates among them?A simple algorithm is to compare each possible pair in the list to see if there are any duplicates. But this algorithm runs in O(n2) time. We can use the following simple algorithm using the set data structure. This…