QA·C Help - 1520

	1520	Functions are indirectly recursive.

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A group of functions have been identified which appears to form a recursive sequence.

In general most recursive functions can be replaced with a stack and loop and in most cases the performance and scalability of the code will be improved.

Amongst others, recursive functions have two main drawbacks:

the functions are relatively slow
stack size may be limited on some systems

When asked to write a program which calculates the factorial of a number, it is common enough to see that a recursive function is used. Although a good example of what a recursive function is, this is a very bad example of when to use a recursive function.

Example:


int recursiveFactorial(int i)
{
  if (1 == i)
  {
    return i;
  }
  else
  {
    return i * recursiveFactorial (i - 1);
  }
}

int loopFactorial(int i)
{
  int result = 1;
  for (; i > 1; --i)
  {
    result *= i;
  }
  return result;
}

Even in these small examples above, for large values of 'i', the recursive implementation can take up to twice as long as the non recursive version.

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