Add solution #1657

Author: JoshCrozier

README.md

@@ -333,6 +333,7 @@
 1566|[Detect Pattern of Length M Repeated K or More Times](./1566-detect-pattern-of-length-m-repeated-k-or-more-times.js)|Easy|
 1576|[Replace All ?'s to Avoid Consecutive Repeating Characters](./1576-replace-all-s-to-avoid-consecutive-repeating-characters.js)|Medium|
 1598|[Crawler Log Folder](./1598-crawler-log-folder.js)|Easy|
+1657|[Determine if Two Strings Are Close](./1657-determine-if-two-strings-are-close.js)|Medium|
 1668|[Maximum Repeating Substring](./1668-maximum-repeating-substring.js)|Easy|
 1669|[Merge In Between Linked Lists](./1669-merge-in-between-linked-lists.js)|Medium|
 1672|[Richest Customer Wealth](./1672-richest-customer-wealth.js)|Easy|

solutions/1657-determine-if-two-strings-are-close.js

@@ -0,0 +1,47 @@
+/**
+ * 1657. Determine if Two Strings Are Close
+ * https://leetcode.com/problems/determine-if-two-strings-are-close/
+ * Difficulty: Medium
+ *
+ * Two strings are considered close if you can attain one from the other using the following
+ * operations:
+ *
+ * - Operation 1: Swap any two existing characters.
+ *   For example, abcde -> aecdb
+ * - Operation 2: Transform every occurrence of one existing character into another existing
+ *   character, and do the same with the other character.
+ *   For example, aacabb -> bbcbaa (all a's turn into b's, and all b's turn into a's)
+ *
+ * You can use the operations on either string as many times as necessary.
+ *
+ * Given two strings, word1 and word2, return true if word1 and word2 are close, and false
+ * otherwise.
+ */
+
+/**
+ * @param {string} word1
+ * @param {string} word2
+ * @return {boolean}
+ */
+var closeStrings = function(word1, word2) {
+  const map1 = helper(word1);
+  const map2 = helper(word2);
+
+  for (let i = 0; i < map1.length; i++) {
+    if ((map1[i] === 0 || map2[i] === 0) && map1[i] !== map2[i]) {
+      return false;
+    }
+  }
+
+  [map1, map2].forEach(m => m.sort((a, b) => b - a));
+
+  return map1.join('') === map2.join('');
+};
+
+function helper(input) {
+  const map = Array(26).fill(0);
+  for (let i = 0; i < input.length; i++) {
+    map[input.charCodeAt(i) - 'a'.charCodeAt(0)]++;
+  }
+  return map;
+}