「自作Python100本ノック」12日目（81本〜88本目） ref: https://qiita.com/ahpjop/items/e86f361e903e3adb6f84

q81.py

from itertools import combinations

def twosums(x, target):
    for item in combinations(x, 2):
            if sum(item) == target:
                return item

nums = [2, 7, 11, 15]
target = 9
twosums(nums, target)

q82.py

def reverse_integer(x):
    return int(str(x)[::-1])

reverse_integer(1534236469)

q83.py

def roman_to_int(roman):
    values={'M': 1000, 'D': 500, 'C': 100, 'L': 50, 
                                'X': 10, 'V': 5, 'I': 1}
    """Convert from Roman numerals to an integer."""
    numbers = []
    for char in roman:
        numbers.append(values[char]) 
    total = 0
    for num1, num2 in zip(numbers, numbers[1:]):
        if num1 >= num2:
            total += num1
        else:
            total -= num1
    return total + num2

roman_to_int("XI")

q84.py

def isvalid(x):
    table = {'(': ')', '{': '}', '[': ']'}
    stack = []
    for elm in x:
        if elm in table.keys():
            stack.append(table[elm])
        elif elm in table.values() and elm != stack.pop():
                return False
    return False if len(stack) else True

isvalid('[aaa]'), isvalid('('), isvalid('()[]{}'), isvalid('(]'), isvalid('([)]'), isvalid('{()}')

q85.py

stre = 'パタトクカシーー'
print(stre[0::2])#str[::2]でも同様

q86.py

str1 = 'パトカー'
str2 = 'タクシー'

print(''.join([a + b for a, b in zip(str1, str2)]))

q87.py

strr = "Now I need a drink, alcoholic of course, after the heavy lectures involving quantum mechanics."
strr = strr.replace('.', "")
strr = strr.replace(',', "")
strr = strr.split()

a_list = []

for word in strr:
    a_list.append(len(word))

print(list)

q88.py

import random

text = "I couldn't believe that I could actually understand what I was reading : the phenomenal power of the human mind ."
words = text.split()
shuffled_list = []

for word in words:
    if len(word) < 4:
        pass
    else:
        char_list = list(word)
        mid_list = char_list[1:-1]
        random.shuffle(mid_list)
        word = word[0] + "".join(mid_list) + word[-1]
    shuffled_list.append(word)

shuffled_str = " ".join(shuffled_list)
print(shuffled_str)