Add solution #3090

Author: JoshCrozier

README.md

@@ -2164,6 +2164,7 @@
 3083|[Existence of a Substring in a String and Its Reverse](./solutions/3083-existence-of-a-substring-in-a-string-and-its-reverse.js)|Easy|
 3084|[Count Substrings Starting and Ending with Given Character](./solutions/3084-count-substrings-starting-and-ending-with-given-character.js)|Medium|
 3085|[Minimum Deletions to Make String K-Special](./solutions/3085-minimum-deletions-to-make-string-k-special.js)|Medium|
+3090|[Maximum Length Substring With Two Occurrences](./solutions/3090-maximum-length-substring-with-two-occurrences.js)|Easy|
 3105|[Longest Strictly Increasing or Strictly Decreasing Subarray](./solutions/3105-longest-strictly-increasing-or-strictly-decreasing-subarray.js)|Easy|
 3108|[Minimum Cost Walk in Weighted Graph](./solutions/3108-minimum-cost-walk-in-weighted-graph.js)|Hard|
 3110|[Score of a String](./solutions/3110-score-of-a-string.js)|Easy|

solutions/3090-maximum-length-substring-with-two-occurrences.js

@@ -0,0 +1,31 @@
+/**
+ * 3090. Maximum Length Substring With Two Occurrences
+ * https://leetcode.com/problems/maximum-length-substring-with-two-occurrences/
+ * Difficulty: Easy
+ *
+ * Given a string s, return the maximum length of a substring such that it contains at most
+ * two occurrences of each character.
+ */
+
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var maximumLengthSubstring = function(s) {
+  let result = 0;
+  const map = new Map();
+
+  for (let left = 0, right = 0; right < s.length; right++) {
+    map.set(s[right], (map.get(s[right]) || 0) + 1);
+
+    while (map.get(s[right]) > 2) {
+      map.set(s[left], map.get(s[left]) - 1);
+      if (map.get(s[left]) === 0) map.delete(s[left]);
+      left++;
+    }
+
+    result = Math.max(result, right - left + 1);
+  }
+
+  return result;
+};