题解 | 进制转换
import sys
num_16 = input()
num_16 = num_16[2:]
l = len(num_16)
rule = {"A": 10, "B": 11, "C": 12, "D": 13, "E": 14, "F": 15,"a": 10, "b": 11, "c": 12, "d": 13, "e": 14, "f": 15}
num_10 = 0
for i in range(l):
if num_16[i] in rule.keys():
n = rule[num_16[i]] * 16 ** (l-1-i)
else:
n = int(num_16[i]) * 16 **(l-1-i)
num_10 += n
print(num_10)
