Easy_60_125_Valid Palindrome.java

public class Solution {
    public boolean isPalindrome(String s) {
        int len=s.length();
        if(len==0||len==1)
            return true;
        int i=0,j=len-1;
        while(i<j) {
            char ch1=s.charAt(i);
            char ch2=s.charAt(j);
            if(ch1>='A'&&ch1<='Z')
            	ch1+=32;
            if(ch2>='A'&&ch2<='Z')
            	ch2+=32;
            if (!((ch1>='a'&&ch1<='z') || (ch1>='0' && ch1<='9'))) {
                i++;
                continue;
            }
            if (!((ch2>='a'&&ch2<='z') || (ch2>='0' && ch2<='9'))) {
                j--;
                continue;
            }
            if(ch1!=ch2)
                return false;
            else {
                i++;
                j--;
            }
        }
        return true;
    }
}