Given a 32-bit signed integer, reverse digits of an integer.
Example 1:
Input: 123 Output: 321
Example 2:
Input: -123 Output: -321
Example 3:
Input: 120 Output: 21
Note:
Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: [−231, 231 − 1]. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.
func reverse(x int) int {
ret :=0
for ;x!=0;x/=10{
ret = ret*10+x%10
if ret > math.MaxInt32 || ret < -math.MaxInt32-1 {
return 0
}
}
return ret
}
*
用math.MaxInt32表示32位最大数
反转用取余乘10的方式
x!=0,因为分正负