腾讯面试题：走台阶

题目：有50个台阶，一次只能走一步或是两步，问走完这五十个台阶，有多少种可能的走法？

1、用递归方法实现

#include <stdio.h>#include <stdlib.h>double go(int n){if(n == 1){return 1.0;}else if(n == 2){return 2.0;}else{return go(n-1)+go(n-2);}}int main(){printf("%f",go(10));return 0;}

2、用for循环

#include <stdio.h>#include <stdlib.h>int main(){double a[50];int i;a[0] = 1;a[1] = 2;for(i = 2; i < 50; i++){a[i] = a[i-1] + a[i-2];}printf("%f",a[49]);return 0;}