LeetCode - Valid Palindrome

通过Large Judge还挺不容易

public class Solution {
    public boolean isPalindrome(String s) {
        int i=0, j=s.length()-1;
        while (i < j) {
            char ci=' ', cj=' ';
            while (i<j && !isLegit(ci = s.charAt(i)))
                i++;
            while (i<j && !isLegit(cj = s.charAt(j)))
                j--;
            if (i<j && !isSame(ci, cj))
                return false;
            i++;
            j--;
        }
        return true;
    }
    
    private boolean isLegit(char c) {
        if (c>='A'&&c<='Z' || c>='a'&&c<='z' || c>='0'&&c<='9')
            return true;
        else
            return false;
    }
    
    private boolean isSame(char ci, char cj) {
        int diff = (int)(ci-cj);
        if (Math.abs(diff)==32 || diff==0)
            return true;
        else
            return false;
    }
}