Recursion

• Three basic structures in programming
  • 1 - top-down execution of programs
    • obvious
  • 2 - selection structures
    • branching of program execution based on selection (if, if-else, …)
  • 3 - repetition structures
    • loops
      • “iteration”
    • another way to do repetition: recursion

• Princeton Introduction to Java Programming notes on Recursion
  • Lab Activity: Write iterative and recursive versions of a method that prints the factorial of an int N,

            // Method headers
            public void printFactorialIterative( int N )

            public void printFactorialRecursive( int N )
            

            
            
            // Calling printFactorial with input N = 4:
            printFactorialIterative(4);
            
            printFactorialRecursive(4);            



            
            // Expected output of both methods:
            4 * 3 * 2 * 1 = 24