fibtrace.cpp

来自「BigC++的源码」· C++ 代码 · 共 30 行

#include <iostream>

using namespace std;

/**
   Computes a Fibonacci number.
   @param n an integer
   @return the nth Fibonacci number
*/
int fib(int n)
{  
   cout << "Entering fib: n = " << n << "\n";
   int f;
   if (n <= 2) f = 1;
   else f = fib(n - 1) + fib(n - 2);
   cout << "Exiting fib: n = " << n
      << " return value = " << f << "\n";
   return f;
}

int main()
{  
   cout << "Enter n: ";
   int n;
   cin >> n;
   int f = fib(n);
   cout << "fib(" << n << ") = " << f << "\n";
   return 0;
}