题解 | 进制转换
import sys
a = input()
hex =a[2:]
h = {
"A":10,
"B":11,
"C":12,
"D":13,
"E":14,
"F":15
}
aplha="ABCDEF"
aplhaLen=len(hex)
num=0
for i in hex:
if i in aplha:
num += int(h[str(i)])*16**(aplhaLen-1)
aplhaLen-=1
else:
num += int(i)*16**(aplhaLen-1)
aplhaLen-=1
print(num)