[leetcode]Palindrome Number

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

123454321 is a Palindrome Number while -123454321 is not，注意stack overflow问题

可以Reuse Reverse Integer的code:

package leetcode;

public class PalindromeNumber {
    public int reverse(int x){
        if(x < 0)return 0;
        boolean isNagtive = false;
        if (x<0){
            isNagtive = true;
            x = -x;
        }
        long y = 0;
        while (x/10 > 0){
            y = y*10 + x%10;
            x /= 10;
        }
        y = y*10 + x;
        if (y>0x7fffffff) return 0; //overflow check.
        if(isNagtive)y = -y;
        return (int)y;
    }

    public boolean isPalindrome(int x) {
        if(reverse(x) == x)return true;
        return false;
    }
}

思考，用递归怎么解决？

---

---

blog comments powered by Disqus

Published

Tags

• leetcode 8