fib_iter.c

来自「c和指针的配书源码」· C语言 代码 · 共 22 行

/*
** Compute the value of the n'th Fibonacci number, iteratively.
*/

long
fibonacci( int n )
{
	long	result;
	long	previous_result;
	long	next_older_result;

	result = previous_result = 1;

	while( n > 2 ){
		n -= 1;
		next_older_result = previous_result;
		previous_result = result;
		result = previous_result + next_older_result;
	}
	return result;
}