valid palindrome solved

Author: sora0319

valid-palindrome/sora0319.java

@@ -0,0 +1,27 @@
+class Solution {
+    public boolean isPalindrome(String s) {
+        int start = 0;
+        int end = s.length()-1;
+
+        boolean isPalindrome = true;
+        s = s.toLowerCase();
+
+        while(start <= end){
+            if((s.charAt(start) < 'a' || s.charAt(start) > 'z') && (s.charAt(start) < '0' || s.charAt(start) > '9')){
+                start++;
+                continue;
+            }
+            if((s.charAt(end) < 'a' || s.charAt(end) > 'z') && (s.charAt(end) < '0' || s.charAt(end) > '9')){
+                end--;
+                continue;
+            }
+            if(s.charAt(start) != s.charAt(end)) return false;
+            start++;
+            end--;
+
+        }
+
+        return isPalindrome;
+    }
+}
+