CS210 Lab: Recursion Postlab Answers

Postlab Answers:

int Puzzle (int base, int limit)
{
	if (base > limit)
		return -1;
	else
		if (base == limit)
			return 1;
		else
			return base* Puzzle(base+1, limit);
}

1. Identify the following:
   1. the base case(s) of the function Puzzle
      1. if (base > limit), return -1;
      2. else if (base == limit), return 1;

   2. the general (recursive) case(s) of the function Puzzle
          if (base < limit), return base* Puzzle(base+1, limit);

2. Show what would be written by the following calls to the recursive function Puzzle
   1. cout << Puzzle(20,5);
          -1
      because it hits the base case:
      if (base > limit), return -1

   2. cout << Puzzle(3,6);
          60
      because it results in something like the following:
       3 * Puzzle(4,6);
       3 * 4 * Puzzle(5,6);
       3 * 4 * 5 * Puzzle(6,6);
       3 * 4 * 5 * 1
      

   3. cout << Puzzle(8,8);
          1
      because it hits the base case:
      else if (base == limit), return 1;