Add solution #680

Author: JoshCrozier

README.md

@@ -166,6 +166,7 @@
 645|[Set Mismatch](./0645-set-mismatch.js)|Medium|
 648|[Replace Words](./0648-replace-words.js)|Medium|
 653|[Two Sum IV - Input is a BST](./0653-two-sum-iv-input-is-a-bst.js)|Easy|
+680|[Valid Palindrome II](./0680-valid-palindrome-ii.js)|Easy|
 686|[Repeated String Match](./0686-repeated-string-match.js)|Easy|
 695|[Max Area of Island](./0695-max-area-of-island.js)|Medium|
 700|[Search in a Binary Search Tree](./0700-search-in-a-binary-search-tree.js)|Easy|

solutions/0680-valid-palindrome-ii.js

@@ -0,0 +1,34 @@
+/**
+ * 680. Valid Palindrome II
+ * https://leetcode.com/problems/valid-palindrome-ii/
+ * Difficulty: Easy
+ *
+ * Given a string s, return true if the s can be palindrome after deleting at most one
+ * character from it.
+ */
+
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+var validPalindrome = function(s) {
+  for (let left = 0, right = s.length - 1; left < right; left++, right--) {
+    if (s[left] !== s[right]) {
+      return isPalindrome(s, left + 1, right) || isPalindrome(s, left, right - 1);
+    }
+  }
+
+  return true;
+};
+
+function isPalindrome(s, left, right) {
+  while (left < right) {
+    if (s[left] !== s[right]) {
+      return false;
+    }
+    right--;
+    left++;
+  }
+
+  return true;
+}