Feat: Add solution of valid-palindrome

Author: easyone

contains-duplicate/easyone-jwlee.go

@@ -7,4 +7,4 @@ func containsDuplicate(nums []int) bool {
 		m[num] = num
 	}
 	return false
-}
+}

valid-palindrome/easyone-jwlee.go

@@ -0,0 +1,20 @@
+func isPalindrome(s string) bool {
+	s = strings.ToLower(s)
+	validStr := ""
+	for _, str := range s {
+		if ('a' > str || 'z' < str) && ('0' > str || '9' < str) {
+			continue
+		}
+		validStr += string(str)
+	}
+	if len(validStr) <= 1 {
+		return true
+	}
+	l := len(validStr)
+	for i := 0; i < l/2; i++ {
+		if validStr[i] != validStr[l-1-i] {
+			return false
+		}
+	}
+	return true
+}