编辑代码

#include <stdio.h>

int footstep(int n){
    if(n < 1) return 0;   
    else if(n == 1) return 1; 
    else if(n == 2) return 2;
    else return footstep(n-1) + footstep(n-2);
}

int main () {
    printf("0个台阶有 %d 种走法\n", footstep(0));
    printf("1个台阶有 %d 种走法\n", footstep(1));
    printf("2个台阶有 %d 种走法\n", footstep(2));
    printf("3个台阶有 %d 种走法\n", footstep(3));
    printf("4个台阶有 %d 种走法\n", footstep(4));
    return 0;
}