package valid_palindrome

import (
	"regexp"
	"strings"
)

var notAlphanumeric = regexp.MustCompile(`[^a-zA-Z0-9]`)

func KeepAlphanumeric(text string) string {
	return notAlphanumeric.ReplaceAllString(text, "")
}

func IsPalindrome(text string) bool {
	scrubbed := strings.ToLower(KeepAlphanumeric(text))

	start := 0
	end := len(scrubbed) - 1

	for start < end {
		if scrubbed[start] != scrubbed[end] {
			return false
		}

		start++
		end--
	}

	return true
}