Oct 3, 2020 · Oct 3, 2020
diff --git a/Leetcode/Leetcode_August_Challenge/Valid_Palindrome.java b/Leetcode/Leetcode_August_Challenge/Valid_Palindrome.java
 package Leetcode_August_Challenge;

 public class Valid_Palindrome {

    public boolean isPalindrome(String s) {
         // check string if it's null no need to go further direct return false

            if(s==null){
            return false;
            }

        // if string contain some char as uppercase or lowercase
        // this will convert whole string to lowercase
        s = s.toLowerCase();

        // pointed i to intially at 0
        // and j to end of the string (last character)
        int i=0;
        int j=s.length()-1;


        while(i<j){
            //if i<j and string char contain a-z and 0-9 loop -> true

            while(i<j && !((s.charAt(i)>='a' && s.charAt(i)<='z')
                        || (s.charAt(i)>='0'&&s.charAt(i)<='9'))){
                i++;
            }

            while(i<j && !((s.charAt(j)>='a' && s.charAt(j)<='z')
                        || (s.charAt(j)>='0'&&s.charAt(j)<='9'))){
                j--;
            }
            // if one of string char not match i to j
            // it will return false
            if(s.charAt(i) != s.charAt(j)){
                return false;
            }

            i++;
            j--;
        }
     // else return true
        return true;

        }
 }
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,47 @@
		package Leetcode_August_Challenge;

		public class Valid_Palindrome {

		public boolean isPalindrome(String s) {
		// check string if it's null no need to go further direct return false

		if(s==null){
		return false;
		}

		// if string contain some char as uppercase or lowercase
		// this will convert whole string to lowercase
		s = s.toLowerCase();

		// pointed i to intially at 0
		// and j to end of the string (last character)
		int i=0;
		int j=s.length()-1;


		while(i<j){
		//if i<j and string char contain a-z and 0-9 loop -> true

		while(i<j && !((s.charAt(i)>='a' && s.charAt(i)<='z')
		\|\| (s.charAt(i)>='0'&&s.charAt(i)<='9'))){
		i++;
		}

		while(i<j && !((s.charAt(j)>='a' && s.charAt(j)<='z')
		\|\| (s.charAt(j)>='0'&&s.charAt(j)<='9'))){
		j--;
		}
		// if one of string char not match i to j
		// it will return false
		if(s.charAt(i) != s.charAt(j)){
		return false;
		}

		i++;
		j--;
		}
		// else return true
		return true;

		}
		}