list0510.cpp

teach yourself C++ in 21 days 第五版

// Fibonacci series using recursion
#include <iostream>
int fib (int n);
  
int main()
{
  
   int n, answer;
   std::cout << "Enter number to find: ";
   std::cin >> n;
  
   std::cout << "\n\n";
  
   answer = fib(n);
  
   std::cout << answer << " is the " << n;
   std::cout << "th Fibonacci number\n";
   return 0;
}
  
int fib (int n)
{
   std::cout << "Processing fib(" << n << ")... ";
  
   if (n < 3 )
   {
      std::cout << "Return 1!\n";
      return (1);
   }
   else
   {
      std::cout << "Call fib(" << n-2 << ") ";
      std::cout << "and fib(" << n-1 << ").\n";
      return( fib(n-2) + fib(n-1));
   }
}