实现一个函数求第n个斐波那契数。



#define_CRT_SECURE_NO_WARNINGS 1

#include<stdio.h>

#include<stdlib.h>

intfun(int n)

{

   
int n1=1,n2=1;

      
int n3=n1;

      
while(n>2)

      
{

             
n3=n1+n2;

             
n1=n2;

             
n2=n3;

             
n--;

      
}

      
return n3;

}

intmain()

{

      
int n=0;

      
int ret=0;

      
scanf("%d\n",n);

      
ret=fun(n);

      
printf("%d\n",ret);

      
system("pause");

      
return 0;