7. Reverse Integer.go

循环取余数
需要注意越界

func reverse(x int) int {

    res := 0
    for x != 0 {
        carry := x % 10
        res = res*10 + carry
        if res > math.MaxInt32 || res < math.MinInt32 {
            return 0
        }
        x /= 10
    }
    return res
}