add 242

Author: awesomelike

easy/242-valid-anagram.js

@@ -0,0 +1,26 @@
+/**
+ * @param {string} s
+ * @param {string} t
+ * @return {boolean}
+ */
+ var isAnagram = function(s, t) {
+  if (s === "" || t === "") return true;
+  if (s.length !== t.length) return false;
+  
+  const map = {};
+  for (let i=0; i<s.length; i++) {
+    const l = s[i];
+    if (!map[l]) map[l] = 0;
+    map[l]++;
+  }
+  for (let i=0; i<t.length; i++) {
+    const l = t[i];
+    if (map[l]) {
+      map[l]--;
+      if (map[l] === 0) {
+        delete map[l];
+      }
+    } 
+  }
+  return !Object.keys(map).length;
+};