Hey there! Welcome to ClearUrDoubt.com. In this post, we will look at a simple program to filter positive numbers from a List of integers in Scala. We can achieve this by applying filter method on the input list or using Read more
Hey there! Welcome to ClearUrDoubt.com. In this post, we will look at a Scala program to implement merge sort. Merge Sort is an efficient sorting algorithm. It uses Divide and Conquer algorithm technique. Let’s look at the sample program:
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package com.clearurdoubt /** * Merge Sort is a divide and conquer algorithm. * * We have to divide the initial list into two halves and sort those lists and merge them once they are sorted. * */ object MergeSort extends App { def mergeSort(input: List[Int]) : List[Int] = { val middle = input.length / 2 if(middle == 0) input else { def merge(xs: List[Int], ys: List[Int]): List[Int] = (xs, ys) match { case (Nil, ys) => ys case (xs, Nil) => xs case (x :: xs1, y :: ys1) => if (x < y) x :: merge(xs1, ys) // append x and merge(remaining elements of xs (i.e., xs1), ys) else y :: merge(xs, ys1) // append y and merge(xs , remaining elements of ys (i.e., ys1)) } val (left, right) = input splitAt middle // Split the list into two halves merge(mergeSort(left), mergeSort(right)) // Apply merge on the sorted halves } } val numbers = List(2, -4, 4, 6, 1) println("Input: " + numbers) println("Reversed: " + mergeSort(numbers)) } |
Hey there! Welcome to ClearUrDoubt.com. In this post, we will look at a simple program to reverse a List of elements without using utility method(reverse) in Scala. Let’s look at the program:
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package com.clearurdoubt object Reversing { def main(args: Array[String]) { val list = List(3,4,5,1,2,3) val rev = reversed(list) println(rev + " @@ " + list.reverse) } def reversed(input: List[Int]): List[Int] = input match { case List() => input case x :: xs => reversed(xs) ::: List(x) } } |
Output: Happy Learning. Please leave a reply Read more
Hey there! Welcome to ClearUrDoubt.com. In this post, we will look at a Scala program to find Factorial of a given number using Tail Recursion. Tail Recursion: If a function calls itself as the last action in the definition, it Read more
Hey there! Welcome to ClearUrDoubt.com. In this post, we will look at a Scala program to find Factorial of a given number using Linear Recursion. Let’s look at the program:
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package com.clearurdoubt object Factorial extends App { def factorial(n: Int) : Int = { if (n == 0) 1 else n * factorial(n-1) // Linear Recursion } println(factorial(10)) } |
Output: Currently this program uses Linear Recursion for finding Read more
Hey there! Welcome to ClearUrDoubt.com. In this post, we will look at a Scala program to add all Array elements to a Set object. We can use array.toSet() method or Set.apply() method to add all the elements of an Array Read more
Hey there! Welcome to ClearUrDoubt.com. In the below post, we have seen how to sort List objects using Ordered trait. Sorting a List of custom objects using Ordered trait in Scala Today we will look at a Scala program to sort Read more
Hey there! Welcome to ClearUrDoubt.com. In this post, we will look at a program to demonstrate List and ListBuffer objects in Scala. List is an immutable collection object whereas ListBuffer is a mutable collection object. List provides a way to add Read more
Hey there! Welcome to ClearUrDoubt.com. In this post, we will look at a program to demonstrate Array and ArrayBuffer objects in Scala. Scala arrays are similar to Java arrays. ArrayBuffer will provide a way to add elements at the Read more
Hey there! Welcome to ClearUrDoubt.com. In this post, we will look at the Option type in Scala. Scala has a special type called “Option” to handle optional values. In programming world, sometimes a variable will have null instead of actual Read more