[c语言]用递归和非递归求第n个斐波那契数

代码

//1.1递归求第n个斐波那契数
#include<stdio.h>
int fib(int n)
{
 if(n<=2)
  return 1;
 else
  return fib(n-1)+fib(n-2);
}
int main()
{
 int n = 0;
 printf("请输入你要查找第几个斐波那契数：\n");
 scanf("%d",&n);
 printf("第%d个斐波那契数为%d\n",n,fib(n));
 return 0;
}
//1.2非递归求第n个斐波那契数
#include<stdio.h>
int fib(int n)
{
 int i = 0;
 int a = 1;
 int b = 1;
 int c = 1;
 for(i=0; i<n-2; i++)
 {
  c = a+b;
  a = b;
  b = c;
 }
 return c;
}
int main()
{
 int n = 0;
 printf("请输入你要查找第几个斐波那契数：\n");
 scanf("%d",&n);
 printf("第%d个斐波那契数为%d\n",n,fib(n));
 return 0;
}