diff --git a/best-time-to-buy-and-sell-stock/sunjae95.js b/best-time-to-buy-and-sell-stock/sunjae95.js
new file mode 100644
index 000000000..b49f26827
--- /dev/null
+++ b/best-time-to-buy-and-sell-stock/sunjae95.js
@@ -0,0 +1,28 @@
+/**
+ * @description
+ * brainstorming:
+ * brute force
+ *
+ * time complexity: O(n)
+ * space complexity: O(1)
+ */
+var maxProfit = function (prices) {
+  let answer, min, max;
+  prices.forEach((price, i) => {
+    if (i === 0) {
+      min = price;
+      max = price;
+      answer = 0;
+      return;
+    }
+
+    if (price > max) max = price;
+    if (price < min) {
+      min = price;
+      max = price;
+    }
+    answer = Math.max(answer, max - min);
+  });
+
+  return answer;
+};
diff --git a/group-anagrams/sunjae95.js b/group-anagrams/sunjae95.js
new file mode 100644
index 000000000..b64afa64e
--- /dev/null
+++ b/group-anagrams/sunjae95.js
@@ -0,0 +1,23 @@
+/**
+ * @description
+ * brainstorming:
+ * brute force + hashtable
+ *
+ * time complexity: O(n* k log k)
+ * space complexity: O(n* k)
+ */
+var groupAnagrams = function (strs) {
+  const map = new Map();
+  const answer = [];
+
+  strs.forEach((str) => {
+    const convertedStr = str.split("").sort().join();
+    if (map.has(convertedStr))
+      map.set(convertedStr, map.get(convertedStr).concat(str));
+    else map.set(convertedStr, [str]);
+  });
+
+  map.forEach((value) => answer.push(value));
+
+  return answer;
+};