feat: valid-palindrome

Author: changchanghwang

valid-palindrome/changchanghwang.go

@@ -0,0 +1,34 @@
+// O(n) time complexity
+// O(n) space complexity
+func isPalindrome(s string) bool {
+	regex, _ := regexp.Compile("[a-zA-Z0-9]")
+	reverseAndFilteredString := ""
+	filteredString := ""
+
+	for _, char := range s {
+		if regex.MatchString(string(char)) {
+			c := strings.ToLower(string(char))
+			reverseAndFilteredString = c + reverseAndFilteredString
+			filteredString += c
+		}
+	}
+
+	return reverseAndFilteredString == filteredString
+}
+
+// O(n) time complexity
+// O(n) space complexity
+func isPalindrome2(s string) bool {
+	reverseAndFilteredString := ""
+	filteredString := ""
+
+	for _, char := range s {
+		if unicode.IsLetter(char) || unicode.IsDigit(char) {
+			c := strings.ToLower(string(char))
+			reverseAndFilteredString = c + reverseAndFilteredString
+			filteredString += c
+		}
+	}
+
+	return reverseAndFilteredString == filteredString
+}