LeetCode 143 Palindrome Number

Determine whether an integer is a palindrome. Do this without extra space.

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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.

分析：

通过除10和取余，可以计算一个逆序的数，比较这两个数是否相等就可以了。

public class Solution {
public boolean isPalindrome(int x) {

if(x < 0)
return false;

int origin = x;
int reverse = 0;
int dig = 0;
while(origin > 0){
dig = origin % 10;
reverse = reverse*10 + dig;
origin = origin/10;
}
if(x == reverse)
return true;
else
return false;

}
}