University:
Stony Brook University
Course:
CSE 114 | Introduction to Object-Oriented Programming
Academic year:

2021
Views:

227

Pages:

2
Author:

Prince Sampson

When should you consider using recursive algorithms when writing a program? Recursive algorithms is an amazing feature that Java has but we can’t use it all time and switch it with iteration algorithms. Recursive algorithms has advantages and disadvantages it will be good to learn them to know when we can use it and when we can’t. Advantages: 1. In some cases recursive algorithms are more readable compare with iteration algorithms. 2. If we already have the algorithms we can make it recursive algorithms and don’t write a new iteration algorithms. 3.Recursion algorithm can point to more straightforward and efficient algorithm specifications 4. the recursive algorithm is shorter than iteration algorithm. Disadvantages: 1. Recursion algorithm is usually slower than iteration algorithm. 2. Recursion algorithm usually use more memory than iteration algorithm for the stack. 3. If the recursive function takes an argument then the recursive algorithm might fail for stack overflow error. 4. Recursion algorithm takes more time to run because it store the value and restore them in recursive. Here’s an example we can see the advantage of less code and see 2 disadvantage of stack overflow error if we increase the number of “ReapetCount” variable and the long run time. public class Recursion { static int RecursiveAlgorithm(int n){ if (n<2) return 1; else return n * RecursiveAlgorithm(n-1); } static int IterationAlgorithm(int n){ if (n < 0) return -1; int fact = 1; for (int i = 1; i <= n; i++) fact *= i ; return fact; } public static void main(String[] args) { int ReapetCount = 10000; // Calculate computing time for Recursive algorithm long startTimeArray1 = System.currentTimeMillis(); RecursiveAlgorithm(ReapetCount); long runTimeArray1 = System.currentTimeMillis() - startTimeArray1; System.out.println(runTimeArray1/1000.0); // Calculate computing time for iteration algorithms. long startTimeArray2 = System.currentTimeMillis(); IterationAlgorithm(ReapetCount); long runTimeArray2 = System.currentTimeMillis() - startTimeArray2; System.out.println(runTimeArray2/1000.0); } }