diff --git a/find-minimum-in-rotated-sorted-array/sukyoungshin.ts b/find-minimum-in-rotated-sorted-array/sukyoungshin.ts
new file mode 100644
index 000000000..c88487fc1
--- /dev/null
+++ b/find-minimum-in-rotated-sorted-array/sukyoungshin.ts
@@ -0,0 +1,6 @@
+// 1. Brute-force (시간복잡도: O(n))
+function findMin(nums: number[]): number {
+  return Math.min(...nums);
+};
+
+// 2 Binary Search (시간복잡도: O(log n))
diff --git a/maximum-depth-of-binary-tree/sukyoungshin.ts b/maximum-depth-of-binary-tree/sukyoungshin.ts
new file mode 100644
index 000000000..bdf0a0853
--- /dev/null
+++ b/maximum-depth-of-binary-tree/sukyoungshin.ts
@@ -0,0 +1,19 @@
+class TreeNode {
+  val: number;
+  left: TreeNode | null;
+  right: TreeNode | null;
+  constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
+    this.val = val === undefined ? 0 : val;
+    this.left = left === undefined ? null : left;
+    this.right = right === undefined ? null : right;
+  }
+}
+
+function maxDepth(root: TreeNode | null): number {
+  if (!root) return 0;
+
+  const leftDepth = maxDepth(root.left);
+  const rightDepth = maxDepth(root.right);
+
+  return Math.max(leftDepth, rightDepth) + 1;
+};
diff --git a/merge-two-sorted-lists/sukyoungshin.ts b/merge-two-sorted-lists/sukyoungshin.ts
new file mode 100644
index 000000000..960f0bd9e
--- /dev/null
+++ b/merge-two-sorted-lists/sukyoungshin.ts
@@ -0,0 +1,54 @@
+class ListNode {
+  val: number;
+  next: ListNode | null;
+  constructor(val?: number, next?: ListNode | null) {
+    this.val = val === undefined ? 0 : val;
+    this.next = next === undefined ? null : next;
+  }
+}
+
+function mergeTwoLists(
+  list1: ListNode | null,
+  list2: ListNode | null
+): ListNode | null {
+  const dummy = new ListNode();
+  let current = dummy;
+
+  const addNode = (val: number) => {
+    current.next = new ListNode(val);
+    current = current.next;
+  };
+
+  while (list1 !== null && list2 !== null) {
+    if (list1.val < list2.val) {
+      addNode(list1.val);
+      list1 = list1.next;
+    } else if (list1.val > list2.val) {
+      addNode(list2.val);
+      list2 = list2.next;
+    } else {
+      addNode(list1.val);
+      addNode(list2.val);
+      list1 = list1.next;
+      list2 = list2.next;
+    }
+  }
+
+  current.next = list1 !== null ? list1 : list2;
+  return dummy.next;
+};
+
+// 2번째 풀이 (재귀)
+function mergeTwoLists2(
+  list1: ListNode | null,
+  list2: ListNode | null
+): ListNode | null {
+  if (!(list1 && list2)) return list1 || list2;
+  if (list1.val < list2.val) {
+    list1.next = mergeTwoLists(list1.next, list2);
+    return list1;
+  } else {
+    list2.next = mergeTwoLists(list1, list2.next);
+    return list2;
+  }
+};