125.valid_palindrome

Author: Deftly

README.md

@@ -9,6 +9,7 @@
 |36|[Valid Sudoku](./leetcode/0036.valid_sudoku/)|[Go](./leetcode/0036.valid_sudoku/36.valid_sudoku.go)|Medium|Completed|
 |49|[Group Anagrams](./leetcode/0049.group_anagrams/)|[Go](./leetcode/0049.group_anagrams/49.group_anagrams.go)|Medium|Completed|
 |121|[Best Time to Buy and Sell Stock](./leetcode/0121.best_time_to_buy_and_sell_stock/)|[Go](./leetcode/0121.best_time_to_buy_and_sell_stock/121.best_time_to_buy_and_sell_stock.go)|Easy|Completed|
+|125|[Valid Palindrome](./leetcode/0125.valid_palindrome/)|[Go](./leetcode/0125.valid_palindrome/125.valid_palindrome.go)|Easy|Completed|
 |128|[Longest Consecutive Sequence](./leetcode/0128.longest_consecutive_sequence/)|[Go](./leetcode/0128.longest_consecutive_sequence/128.longest_consecutive_sequence.go)|Medium|Completed|
 |217|[Contains Duplicate](./leetcode/0217.contains_duplicate/)|[Go](./leetcode/0217.contains_duplicate/217.contains_duplicate.go)|Easy|Completed|
 |238|[Product of Array Except Self](./leetcode/0238.product_of_array_except_self/)|[Go](./leetcode/0238.product_of_array_except_self/238.product_of_array_except_self.go)|Medium|Completed|

leetcode/0125.valid_palindrome/125.valid_palindrome.go

@@ -0,0 +1,28 @@
+package data_structures_algorithms
+
+import (
+	"strings"
+	"unicode"
+)
+
+func isPalindrome(s string) bool {
+	mapFunc := func(r rune) rune {
+		if !unicode.IsLetter(r) && !unicode.IsDigit(r) {
+			return -1
+		}
+
+		return unicode.ToLower(r)
+	}
+
+	s = strings.Map(mapFunc, s)
+
+	i, j := 0, len(s)-1
+	for i < j {
+		if s[i] != s[j] {
+			return false
+		}
+		i++
+		j--
+	}
+	return true
+}

leetcode/0125.valid_palindrome/README.md

@@ -0,0 +1,32 @@
+# [125. Valid Palindrome](https://leetcode.com/problems/valid-palindrome/)
+A phrase is a palindrome if, after converting all uppercase letters to lowercase letters and removing all non-alphanumeric characters, it reads the same forward and backward. Alphanumeric characters include letters and numbers.
+
+Given a string `s`, return `true` if it is a palindrome, or `false` otherwise.
+
+#### Example 1:
+```shell 
+Input: s = "A man, a plan, a canal: Panama"
+Output: true
+Explanation: "amanaplanacanalpanama" is a palindrome.
+```
+
+#### Example 2: 
+```shell 
+Input: s = "race a car"
+Output: false
+Explanation: "raceacar" is not a palindrome.
+```
+
+#### Example 3:
+```shell 
+Input: s = " "
+Output: true
+Explanation: s is an empty string "" after removing non-alphanumeric characters.
+Since an empty string reads the same forward and backward, it is a palindrome.
+```
+
+<br>
+
+#### Constraints:
+- <code>1 <= s.length <= 2 * 10<sup>5</sup></code>
+- `s` consists only of printable ASCII characters.