time=434ms
负数不是回文数
public class Solution { public boolean isPalindrome(int x) { int palindrome=0; int revers=x; if(revers<0) return false; else{ while(revers>0){ int m=revers%10; palindrome=m+palindrome*10; revers=revers/10; } if(palindrome==x) return true; else return false; } } }