c

/*
    __author__ = 'xiaofeizhang'
    函数作用：递归函数实现斐波那契 
*/
#include <stdio.h>
int main(void){
    long fibonacci(int n);
    int num;
    long sum;
    printf("输入斐波那契数值：");
    scanf("%d", &num);
    sum = fibonacci(num);
    printf("%d的斐波那契数列的数值为：%d", num, sum);
    return 0;
} 

long fibonacci(int n){
    long sum;
    if (n==0){
        sum = 0;
    }
    else if (n==1){
        sum = 1;
    } 
    else {
        sum = fibonacci(n-1) + fibonacci(n-2);
    }
    return sum;
}

/*
输入斐波那契数值：20
20的斐波那契数列的数值为：6765
--------------------------------
Process exited after 2.298 seconds with return value 0
请按任意键继续. . .

*/