题解 | #字符串合并处理#

import re
def step3(old_char):
    if re.search(r'[0-9A-Fa-f]', old_char):
        return hex(int(bin(int(old_char, 16))[2:].rjust(4, '0')[::-1], 2))[2:].upper()
    else:
        return old_char
while True:
    try:
        #第一步
        s0 = input()
        s1 = list(s0.replace(' ', ''))
        #第二步
        s_even = []
        s_odd = []
        s2 = ['']*len(s1)
        for i,ch in enumerate(s1):
            if i % 2 == 0:
                s_even.append(ch)
            else:
                s_odd.append(ch)
        s_even.sort()
        s_odd.sort()
        for i in range(len(s_even)):
            s2[2*i] = s_even[i]
        for i in range(len(s_odd)):
            s2[2*i + 1] = s_odd[i]
        #第三步:遍历s2每个元素，对每个元素进行step3的操作
        s3 = ''
        for i in s2:
            s3 += step3(i)
        print(s3)
    except:
        break