小甲鱼Python

P24 023递归：这帮小兔崽子

P24 023递归：这帮小兔崽子

# def fab(n): # n1 = 1 # n2 = 1 # n3 = 1 # # if n < 1: # print('输入有误！') # return -1 # # while(n-2)>0: # n3 = n2 + n1 # n1 = n2 # n2 = n3 # n -= 1 # # # return n3 # # result = fab(20) # if result != -1: # print('共有%d 只兔崽子诞生'% result) def fab(n): if n < 1: print('输入有误') return -1 if n ==1 or n==2: return 1 else: return fab(n-1)+fab(n-2) result =fab(30) if result != -1: print('总共有%d只小兔崽子诞生'%result)