CS61A 2020FALL 学习记录|homework1

#A plus Abs B
from operator import add , sub ,mul
def a_plus_abs_b(a,b):
    if b < 0:
        f = sub
    else:
        f = add
    return f(a,b)

#将三个数中最小的两个数的平方相加，且函数只能写一行
def two_of_three(x,y,z):
    return sub(add(add(mul(x,x),mul(y,y)),mul(z,z)),mul(max(x,y,z),max(x,y,z)))

#求大于1的整数的最大正因子
def largest_factor(n):
    for i in range(n-1,0,-1):
       if n%i == 0:
           return i
    return None

​def if_function(condition,true_result,false_result):
    if condition:
       return true_result
    else:
       return false_result
def with_if_statement():
    if cond():
        return true_func()
    else:
        return false_func()

def with_if_function():
    return if_function(cond(),true_func(),false_func())

def cond():
    return False

def true_func():
    print(42)

def false_func():
    print(47) 

​

这一道题需要注意函数参数在传递时是先求值的。 

#Hailstonw
def hailstone(n):
    i=1
    while n!=1:
          print(n)
          if n%2 == 0:
             n=n//2
          else:
             n=n*3+1
          i=i+1
    print(n)
    return i