Add valid-anagram solution

Author: Jeehay28

valid-anagram/Jeehay28.js

@@ -0,0 +1,55 @@
+/**
+ * @param {string} s
+ * @param {string} t
+ * @return {boolean}
+ */
+
+// 시간 복잡도: O(n)
+// 공간 복잡도: O(n) 
+
+var isAnagram = function (s, t) {
+
+    if (s.length !== t.length) {
+        return false;
+    }
+
+    let obj = {};
+
+    for (let k of s) {
+        obj[k] = (obj[k] || 0) + 1;
+
+    }
+
+    for (let k of t) {
+        if (obj[k] === undefined || obj[k] === 0) {
+            return false;
+        }
+        obj[k]--;
+    }
+
+    return true;
+
+};
+
+// 시간 복잡도: O(n log n)
+// 공간 복잡도: O(n)
+
+// var isAnagram = function (s, t) {
+
+//     if (s.length !== t.length) {
+//         return false;
+//     }
+
+//     let sArr = s.split("").sort();
+//     let tArr = t.split("").sort();
+
+//     for (let i = 0; i < sArr.length; i++) {
+//         if (sArr[i] !== tArr[i]) {
+//             return false;
+//         }
+//     }
+
+//     return true;
+
+// };
+