题解 | #数字颠倒#
数字颠倒
https://www.nowcoder.com/practice/ae809795fca34687a48b172186e3dafe
import sys
a=input()
try:
int(a)
except:
print('invalid input!')
sys.exit()
else:
if int(a)<0 or int(a)>=2**30-1:
print('input out of range!')
sys.exit()
b=a[::-1]
print(b)
