﻿ python – 项目Euler 17 - 代码日志

#### python – 项目Euler 17

If the numbers 1 to 5 are written out in words: one, two, three, four, five, then there are 3 + 3 + 5 + 4 + 4 = 19 letters used in total.

If all the numbers from 1 to 1000 (one thousand) inclusive were written out in words, how many letters would be used?

NOTE: Do not count spaces or hyphens. For example, 342 (three hundred and forty-two) contains 23 letters and 115 (one hundred and fifteen) contains 20 letters. The use of “and” when writing out numbers is in compliance with British usage.

``````# create dict mapping numbers to their
# lengths in English

maps = {}
maps[0] = 0
maps[1] = 3
maps[2] = 3
maps[3] = 5
maps[4] = 4
maps[5] = 4
maps[6] = 3
maps[7] = 5
maps[8] = 5
maps[9] = 4
maps[10] = 3
maps[11] = 6
maps['and'] = 3
maps['teen'] = 4
maps[20] = 6
maps[30] = 6
maps[40] = 5
maps[50] = 5
maps[60] = 6
maps[70] = 7
maps[80] = 6
maps[90] = 6
maps[100] = 7
maps[1000] = 8

# create a list of numbers 1-1000
def int_to_list(number):
s = str(number)
c = []
for digit in s:
a = int(digit)
c.append(a)
return c  # turn a number into a list of its digits
def list_to_int(numList):
s = map(str, numList)
s = ''.join(s)
s = int(s)
return s

L = []
for i in range(1,1001,1):
L.append(i)

def one_digit(n):
q = maps[n]
return q
def eleven(n):
q = maps[11]
return q
def teen(n):
digits = int_to_list(n)
q = maps[digits[1]] + maps['teen']
return q
def two_digit(n):
digits = int_to_list(n)
first = digits[0]
first = first*10
second = digits[1]
q = maps[first] + one_digit(second)
return q
def three_digit(n):
digits = int_to_list(n)
first = digits[0]
second = digits[1]
third = digits[2]

# first digit length
f = maps[first]+maps[100]

if second == 1 and third == 1:
s = maps['and'] + maps[11]
elif second == 1 and third != 1:
s = digits[1:]
s = list_to_int(s)
s = maps['and'] + teen(s)
elif second == 0 and third == 0:
s = maps[0]
elif second == 0 and third != 0:
s = maps['and'] + maps[third]
else:
s = digits[1:]
s = list_to_int(s)
s = maps['and'] + two_digit(s)

q = f + s
return q
def thousand(n):
q = maps[1000]
return q

# generate a list of all the lengths of numbers

lengths = []

for i in L:
if i < 11:
n = one_digit(i)
lengths.append(n)
elif i == 11:
n = eleven(i)
lengths.append(n)
elif i > 11 and i < 20:
n = teen(i)
lengths.append(n)
elif i > 20 and i < 100:
n = two_digit(i)
lengths.append(n)
elif i >= 100 and i < 1000:
n = three_digit(i)
lengths.append(n)
elif i == 1000:
n = thousand(i)
lengths.append(n)
else:
pass

# since "eighteen" has eight letters (not 9), subtract 10
sum = sum(lengths) - 10
print "Your number is: ", sum
``````

>这是错的：

``````maps[60] = 6
``````

>几个青少年错了：

``````>>> teen(12)
7
>>> teen(13)
9
>>> teen(15)
8
>>> teen(18)
9
``````

>和任何数量的形式x10：

``````>>> three_digit(110)
17
``````

>数字20不计算(您认为i <20且i> 20但不是i == 20). 对错误的贡献：-6
>数字1000用英文写成“一千”但是：

``````>>> thousand(1000)
8
``````

>您最后减去10,以尝试补偿其中一个错误.

``````unit_names = """zero one two three four five six seven eight nine ten
eleven twelve thirteen fourteen fifteen sixteen seventeen
eighteen nineteen""".split()
tens_names = """zero ten twenty thirty forty fifty sixty seventy eighty
ninety""".split()

def english(n):
"Return the English name for n, from 0 to 999999."
if n >= 1000:
thous = english(n // 1000) + " thousand"
n = n % 1000
if n == 0:
return thous
elif n < 100:
return thous + " and " + english(n)
else:
return thous + ", " + english(n)
elif n >= 100:
huns = unit_names[n // 100] + " hundred"
n = n % 100
if n == 0:
return huns
else:
return huns + " and " + english(n)
elif n >= 20:
tens = tens_names[n // 10]
n = n % 10
if n == 0:
return tens
else:
return tens + "-" + english(n)
else:
return unit_names[n]

def letter_count(s):
"Return the number of letters in the string s."
import re
return len(re.findall(r'[a-zA-Z]', s))

def euler17():
return sum(letter_count(english(i)) for i in range(1, 1001))
``````

``````>>> english(967)
'nine hundred and sixty-seven'
``````