Leetcode 9 Palindrome Number

Description

Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.

Example:

Example 1:
Input: 121
Output: true


Example 2:
Input: -121
Output: false
Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.


Example 3:
Input: 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.

解题思路

根据题目要求求出一个数是否是回文数,只需要使用 y=y*10+tempx%10;tempx/=10;这两个语句便可以求出翻转后的数,在于一起拿的书比较就可以求出是否回文。

AC代码

1
2
3
4
5
6
7
8
9
10
11
12
class Solution {
public:
bool isPalindrome(int x) {
if(x<0||(x%10==0&&x!=0)) return false;
int y=0,tempx=x;
while(tempx){
y=y*10+tempx%10;
tempx/=10;
}
return x==y;
}
};

题目链接

Palindrome Number