125. 验证回文串

package leetcode;

public class demo_125 {
    public boolean isPalindrome(String s) {
        if(s=="") {return true;}
        int left=0;
        int right=s.length()-1;
        while(left<right) {
            char l=s.charAt(left);
            char r=s.charAt(right);
            //判断字符是否是数字或者是大小写字符
            if(l<48||l>122||(l>90&&l<97)||(l>57&&l<65)) {
                left=left+1;
                continue;
            }
            if(r<48||r>122||(r>90&&r<97)||(r>57&&r<65)) {
                right=right-1;
                continue;
            }
            //如果是大写字母全部变成小写字母
            if(l>64&&l<91) {
                l=(char)(l+32);
            }
            if(r>64&&r<91) {
                r=(char)(r+32);
            }
            if(l!=r) {
                return false;
            }
            left=left+1;
            right=right-1;
        }
        return true;
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        demo_125 d125=new demo_125();
        String string="A man, a plan, a canal: Panama";
        System.out.println(d125.isPalindrome(string));
    }

}