Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.
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.
思路:反向计算出来值,然后跟原来的值比较就可以了。注意:保存原来的值;
class Solution {
public boolean isPalindrome(int x) {
if(x < 0) {
return false;
}
int num = 0;
int origin = x;
while(x != 0) {
num = num * 10 + x % 10;
x = x / 10;
}
return num == origin;
}
}