added Function

Author: mauricechouam

Find All Anagrams in a String/code.js

@@ -0,0 +1,33 @@
+/*
+ * @param {string} s
+ * @param {string} p
+ * @return {number[]}
+ */
+var findAnagrams = function(s, p) {    
+    const results = [];
+    const map = new Map();
+    for (const letter of p) {
+        map.set(letter, (map.get(letter) || 0) + 1);
+    }
+    
+    let needed = map.size;
+    for (let i = 0, j = 0; j < s.length; j++) {
+        const left = s[i], right = s[j];
+        
+        if (map.has(right)) {
+            map.set(right, map.get(right) - 1);
+            if (!map.get(right)) needed--;
+        }
+        
+        if (j - i + 1 === p.length) {
+            if (!needed) results.push(i);
+            if (map.has(left)) {
+                const previous = map.get(left);
+                map.set(left, map.get(left) + 1);
+                if (map.get(left) > 0 && previous <= 0) needed++;
+            }
+            i++;
+        }
+    }
+    return results;
+};