public class PalindromeNumber {

// 耗时101ms

public boolean isPalindrome(int x) {

if (x < 0) {

return false;

}

int y = 1;

for ( ; y <= x / 10; y *= 10);

for (int t = 1; t < y; t *= 10, y /= 10) {

if ((x / y) % 10 != (x / t) % 10) {

return false;

}

}

return true;

}

/**

* 直接给数倒过来看是否相等

* 耗时103ms

*/

public boolean isPalindrome2(int x) {

if (x < 0) {

return false;

}

int n = 0, m = x;

for ( ; x > 0; x /= 10) {

n = n * 10 + x % 10;

}

return n == m;

}

}