Add solution #438

Author: JoshCrozier

README.md

@@ -286,6 +286,7 @@
 434|[Number of Segments in a String](./0434-number-of-segments-in-a-string.js)|Easy|
 435|[Non-overlapping Intervals](./0435-non-overlapping-intervals.js)|Medium|
 437|[Path Sum III](./0437-path-sum-iii.js)|Medium|
+438|[Find All Anagrams in a String](./0438-find-all-anagrams-in-a-string.js)|Medium|
 441|[Arranging Coins](./0441-arranging-coins.js)|Easy|
 442|[Find All Duplicates in an Array](./0442-find-all-duplicates-in-an-array.js)|Medium|
 443|[String Compression](./0443-string-compression.js)|Medium|

solutions/0438-find-all-anagrams-in-a-string.js

@@ -0,0 +1,40 @@
+/**
+ * 438. Find All Anagrams in a String
+ * https://leetcode.com/problems/find-all-anagrams-in-a-string/
+ * Difficulty: Medium
+ *
+ * Given two strings s and p, return an array of all the start indices of p's anagrams in s.
+ *
+ * You may return the answer in any order.
+ */
+
+/**
+ * @param {string} s
+ * @param {string} p
+ * @return {number[]}
+ */
+var findAnagrams = function(s, p) {
+  const group = new Array(26).fill(0);
+  const result = [];
+
+  for (let i = 0; i < p.length; i++) {
+    group[p.charCodeAt(i) - 97]--;
+  }
+
+  outer: for (let i = 0; i < s.length; i++) {
+    group[s.charCodeAt(i) - 97]++;
+    if (i < p.length - 1) {
+      continue;
+    } else if (i > p.length - 1) {
+      group[s.charCodeAt(i - p.length) - 97]--;
+    }
+    for (let j = 0; j < 26; j++) {
+      if (group[j]) {
+        continue outer;
+      }
+    }
+    result.push(i + 1 - p.length);
+  }
+
+  return result;
+};