Palindrome Number
来源:互联网 发布:西方古代科技成就知乎 编辑:程序博客网 时间:2024/06/18 09:07
Determine whether an integer is a palindrome. Do this without extra space.
click to show spoilers.
Some hints:
Could negative integers be palindromes? (ie, -1)
If you are thinking of converting the integer to string, note the restriction of using extra space.
You could also try reversing an integer. However, if you have solved the problem "Reverse Integer", you know that the reversed integer might overflow. How would you handle such case?
There is a more generic way of solving this problem.
考察的就是对数字每一位的操作。知道了/和%如何工作的那么提出数字的每一位都不是什么难事。只要每次比较数字的第一位和最后一位,看是否相等,然后去掉首位两位进行下一次循环。这里没有溢出什么的事情,还算比较简单。
public class Solution { public boolean isPalindrome(int x) { if(x < 0) return false; int div = 1; int temp = x; while((temp /= 10) > 0) div *= 10; while(x > 0){ //compare the first and the last digit if(x % 10 != x / div) return false; //remove the first digit x %= div; //remove the last digit x /= 10; div /= 100; } return true; }}
0 0
- Palindrome Number
- Palindrome Number
- Palindrome Number
- Palindrome Number
- Palindrome Number
- Palindrome number
- Palindrome Number
- Palindrome Number
- Palindrome Number
- Palindrome Number
- Palindrome Number
- Palindrome Number
- Palindrome Number
- Palindrome Number
- Palindrome Number
- Palindrome Number
- Palindrome Number
- Palindrome Number
- 设计模式——建造者
- [LeetCode] Valid Sudoku
- [NOI2005]瑰丽华尔兹
- Singleton Pattern
- dssdfs
- Palindrome Number
- dfgdfg秩序兴冲冲v
- 的说法了客户的疯狂荣恩替u非的公开了好想的疯狂
- 法规和规范回个和规范好几个个回个刚刚房间方方很疯个很疯
- LINK : fatal error LNK1561: entry point must be defined
- Leetcode: Reverse Linked List II
- embed all fonts in pdf for camera ready version
- Factory Pattern
- java获取cpu,内存,磁盘等信息