Elegence
@ddm coding camp 字数 300 阅读 7
Bool运算符 %d zipmin max
I always thought that my old friend John was rather richer than he looked, but I never knew exactly how much money he actually had. One day (as I was plying him with questions) he said:
"Imagine I have between m and n Zloty..." (or did he say Quetzal? I can't remember!)
"If I were to buy 9 cars costing c each, I'd only have 1 Zloty (or was it Meticals?) left."
"And if I were to buy 7 boats at b each, I'd only have 2 Ringglets (or was it Zloty?) left."
Could you tell me in each possible case:
how much money f he could possibly have ?
the cost c of a car?
the cost b of a boat?
So, I will have a better idea about his fortune. Note that if m-n is big enough, you might have a lot of possible answers.
Each answer should be given as ["M: f", "B: b", "C: c"] and all the answers as [ ["M: f", "B: b", "C: c"], ... ]. "M" stands for money, "B" for boats, "C" for cars.
Note: m, n, f, b, c are positive integers, where 0 <= m <= n or m >= n >= 0. m and n are inclusive.
班主任拨出一笔钱购买文具盒，任务交给我后，我先算了一笔帐，如果买7元一个的剩2元，买9元一个的剩1元。
老师取出一张纸币给我。请问老师给了我多少钱，如果分别买7元和9元的文具盒各能买到几个？
输入参数：自由定义
输出格式：例如['M:37', 'F:5', 'N:4']
“三个都是正整数：M是老师给我的钱，F是5元一个文具盒的数量，N是9元一个文具盒的数量。注意输出示例不能完全满足题意！”
# 假设预算数值的合理范围10，20，50，100
# 人民币发行只有这几种面值超过价格
def howmuch(cash):
for i in cash:
if (i-1) % 9 == 0 and (i-2) % 7 == 0:
f,n = (i-2)//7,(i-1)//9
return [f'{x+str(y)}'for x, y in zip(['M:','F:','S:'],[i,f,n])]
#[f'{x + str(y)}' for x, y in zip(['M:', 'F:', 'S:'], [f, f,n])
cash = [10,20,50,100]
输出结果 ['M:100', 'F:14', 'S:11']
下面的写法列表推导式更简洁！
def howmuch(cash):
return [['M:%d'%i,'B:%d'%(i/7),'C:%d'%(i/9)] for i in cash if i%7 == 2 and i%9 == 1]
请参考下面链接更多f-string格式输出的用法！
name="Eric"
"Hello, %s."%name
'Hello, Eric.'
F"Hello, {name}. You are {age}."
'Hello, Eric. You are 74.'
name = "Eric Idle"
f"{to_lowercase(name)} is funny."
'eric idle is funny.'
name = "Eric"
age = 74
"Hello, %s. You are %s." % (name, age)
class类：f“class”输出
class Comedian:
def __init__(self, first_name, last_name, age):
self.first_name = first_name
self.last_name = last_name
self.age = age
def __str__(self):
return f"{self.first_name} {self.last_name} is {self.age}."
def __repr__(self):
return f"{self.first_name} {self.last_name} is {self.age}. Surprise!"
new_comedian = Comedian("Eric", "Idle", "74")
f"{new_comedian}"
'Eric Idle is 74.'
多行合并输出
name = "Eric"
profession = "comedian"
affiliation = "Monty Python"
message = (
f"Hi {name}. "
f"You are a {profession}. "
f"You were in {affiliation}."
... )
message
'Hi Eric. You are a comedian. You were in Monty Python.'
比较f-string和formate执行速度
>>>import timeit
>>>timeit.timeit("""name = "Eric"
... age = 74
... '%s is %s.' % (name, age)""", number = 10000)
0.003324444866599663
>>> timeit.timeit("""name = "Eric"
... age = 74
... '{} is {}.'.format(name, age)""", number = 10000)
0.004242089427570761
>>> timeit.timeit("""name = "Eric"
... age = 74
... f'{name} is {age}.'""", number = 10000)
0.0024820892040722242
▽ 大咖说 ▽
"It’s not at all important to get it right the first time. It’s vitally important to get it right the last time.” - The Pragmatic Programmer
"第一次就能搞定代码并不重要。更重要的问题，最后一次是正确的。”- 务实的程序员
"Every great developer you know got there by solving problems they were unqualified to solve until they actually did it." - Patrick McKenzie
“每一个伟大的开发者都是解决他们没有能力解决的问题开始的，直到他们真正做到了。
-Patrick McKenzie
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