题解 | #进制转换#

import sys
mapping = {
    '0': 0, '1': 1, '2': 2, '3': 3, '4': 4,
    '5': 5, '6': 6, '7': 7, '8': 8, '9': 9,
    'a': 10, 'b': 11, 'c': 12, 'd': 13, 'e': 14, 'f': 15
}

for x in sys.stdin:
    # 常规方法
    x = x.strip().lower().replace('0x', '')
    if not x:
        continue
    v = 0
    for i, char in enumerate(reversed(list(x))):
        v += mapping[char] * 16 ** i
    print(v)
        
    # 极简方法
    # print(int(x, 16))