[LeetCode]#7.Reverse Integer

Environment: Python 3.7

Key technique: Slice, 32 bit number binary

Example 1:

Input: 123
Output: 321

Example 2:

Input: -123
Output: -321

Example 3:

Input: 120
Output: 21

Analysis:

1. Use slice to get reverse number
2. if the number is negative, Multiply it *-1.
3. Don’t let number exceed 32 bit number.

Solution:

class Solution:
    def reverse(self, x):
        if x>=0:
            ans=int(str(x)[::-1])
        else:
            x=x *-1
            ans=int(str(x)[::-1])*-1
        if ans>2147483647 or ans<-2147483648:
            ans=0
        return ans

Submitted result:

Lesson learn:

The video maximum damage or hp is 2147483647 due to the 32 bit limit.

Reference:

http://www.padpadblog.com/2019/05/2147483647.html?fbclid=IwAR1Y4K_hIbzAJGj_cZYCsIY8eTVBRyWtLZ63FLxD2_kpwtN3a431pptfDhg

https://www.itread01.com/p/521344.html