Write out numbers
Codewars Kata 51√
Description
https://www.codewars.com/kata/52724507b149fa120600031d/solutions/python
-简述：本题给定一个数字，要求讲其转换为文字形式表达。
-思路：分情况讨论，数字过大时需要调用函数自身更为简便
Create a function that transforms any positive number to a string representing the number in words. The function should work for all numbers between 0 and 999999.
Examples number2words(0) ==> “zero” number2words(1) ==> “one” number2words(9) ==> “nine” number2words(10) ==> “ten” number2words(17) ==> “seventeen” number2words(20) ==> “twenty” number2words(21) ==> “twenty-one” number2words(45) ==> “forty-five” number2words(80) ==> “eighty” number2words(99) ==> “ninety-nine” number2words(100) ==> “one hundred” number2words(301) ==> “three hundred one” number2words(799) ==> “seven hundred ninety-nine” number2words(800) ==> “eight hundred” number2words(950) ==> “nine hundred fifty” number2words(1000) ==> “one thousand” number2words(1002) ==> “one thousand two” number2words(3051) ==> “three thousand fifty-one” number2words(7200) ==> “seven thousand two hundred” number2words(7219) ==> “seven thousand two hundred nineteen” number2words(8330) ==> “eight thousand three hundred thirty” number2words(99999) ==> “ninety-nine thousand nine hundred ninety-nine” number2words(888888) ==> “eight hundred eighty-eight thousand eight hundred eighty-eight”
My solution
def number2words(n):
digits = ['zero','one','two','three',
'four','five','six','seven',
'eight','nine','ten','eleven',
'twelve','thirteen','fourteen',
'fifteen','sixteen','seventeen',
'eighteen','nineteen','twenty']
decades = ['ten','twenty','thirty','forty',
'fifty','sixty','seventy','eighty',
'ninety']
if n < 20:
return digits[n]
elif n < 100:
return decades[n//10-1] + ('-' + digits[n % 10] if n % 10 > 0 else '')
elif n < 1000:
return digits[n//100] + ' hundred' + (' '+ number2words(n%100) if n%100>0 else '')
elif n<1000000:
return number2words(n//1000) + ' thousand' + (' '+ number2words(n%1000) if n%1000>0 else '')
print(number2words(869043))
Given solution
def number2words(n):
digits = ['zero','one','two','three',
'four','five','six','seven',
'eight','nine','ten','eleven',
'twelve','thirteen','fourteen',
'fifteen','sixteen','seventeen',
'eighteen','nineteen','twenty']
decades = ['ten','twenty','thirty','forty',
'fifty','sixty','seventy','eighty',
'ninety']
if n < 20:
return digits[n]
elif n < 100:
return decades[n//10-1] + ('' if n % 10 == 0 else '-' + digits[n % 10])
elif n<1000:
return number2words(n//100) + ' hundred' + (' ' + number2words(n % 100) if n % 100 > 0 else '')
elif n<1000000:
return number2words(n // 1000) + " thousand" + (' ' + number2words(n % 1000) if n % 1000 > 0 else '')
print(number2words(869043))
Points
1 不加and，调用函数自身
2 如何提取数字的各位数字
ps: 用到了函数迭代
