Create 125-valid-palindrome.js

Author: everthis

125-valid-palindrome.js

@@ -0,0 +1,37 @@
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+const isPalindrome = function(s) {
+    let start = 0
+    let end = s.length - 1
+
+    let char = ''
+    while(start < end) {
+        while(start < s.length && !valid(s[start])) {
+          start++      
+        }
+        while(end >=0 && !valid(s[end])) {
+          end--      
+        }
+        if(start < s.length && end >=0) {
+          if(s[start].toLowerCase() !== s[end].toLowerCase()) return false           
+        }
+  
+        start++
+        end--
+    }
+  
+    return true
+};
+
+function valid(c) {
+  const code = c.toLowerCase().charCodeAt(0)
+  const zeroCode = ('0').charCodeAt(0)
+  const nineCode = ('9').charCodeAt(0)
+  const aCode = ('a').charCodeAt(0)
+  const zCode = ('z').charCodeAt(0)
+  if( (code >= zeroCode && code <= nineCode) || ( code >= aCode && code <= zCode ) ) return true
+     
+  return false
+}