diff --git a/course-schedule/moonjonghoo.js b/course-schedule/moonjonghoo.js
new file mode 100644
index 000000000..703a36294
--- /dev/null
+++ b/course-schedule/moonjonghoo.js
@@ -0,0 +1,31 @@
+var canFinish = function (numCourses, prerequisites) {
+  const graph = Array.from({ length: numCourses }, () => []);
+  const inDegree = Array(numCourses).fill(0);
+
+  // 그래프 만들기 및 진입 차수 계산
+  for (const [course, pre] of prerequisites) {
+    graph[pre].push(course);
+    inDegree[course]++;
+  }
+
+  // 진입 차수가 0인 노드부터 시작
+  const queue = [];
+  for (let i = 0; i < numCourses; i++) {
+    if (inDegree[i] === 0) queue.push(i);
+  }
+
+  let count = 0;
+  while (queue.length) {
+    const node = queue.shift();
+    count++;
+
+    for (const neighbor of graph[node]) {
+      inDegree[neighbor]--;
+      if (inDegree[neighbor] === 0) {
+        queue.push(neighbor);
+      }
+    }
+  }
+
+  return count === numCourses;
+};
diff --git a/invert-binary-tree/moonjonghoo.js b/invert-binary-tree/moonjonghoo.js
new file mode 100644
index 000000000..bee133d89
--- /dev/null
+++ b/invert-binary-tree/moonjonghoo.js
@@ -0,0 +1,17 @@
+var invertTree = function (root) {
+  if (root === null) return null;
+
+  let queue = [root];
+
+  while (queue.length > 0) {
+    let node = queue.shift();
+
+    // 왼쪽과 오른쪽 자식을 교환
+    [node.left, node.right] = [node.right, node.left];
+
+    if (node.left) queue.push(node.left);
+    if (node.right) queue.push(node.right);
+  }
+
+  return root;
+};
diff --git a/jump-game/moonjonghoo.js b/jump-game/moonjonghoo.js
new file mode 100644
index 000000000..a6799612e
--- /dev/null
+++ b/jump-game/moonjonghoo.js
@@ -0,0 +1,10 @@
+var canJump = function (nums) {
+  let maxReach = 0;
+
+  for (let i = 0; i < nums.length; i++) {
+    if (i > maxReach) return false;
+    maxReach = Math.max(maxReach, i + nums[i]);
+  }
+
+  return true;
+};
diff --git a/search-in-rotated-sorted-array/moonjonghoo.js b/search-in-rotated-sorted-array/moonjonghoo.js
new file mode 100644
index 000000000..36e3c2e50
--- /dev/null
+++ b/search-in-rotated-sorted-array/moonjonghoo.js
@@ -0,0 +1,29 @@
+var search = function (nums, target) {
+  let left = 0,
+    right = nums.length - 1;
+
+  while (left <= right) {
+    const mid = Math.floor((left + right) / 2);
+
+    if (nums[mid] === target) return mid;
+
+    // 왼쪽 절반이 정렬되어 있는 경우
+    if (nums[left] <= nums[mid]) {
+      if (nums[left] <= target && target < nums[mid]) {
+        right = mid - 1; // 왼쪽 범위로 이동
+      } else {
+        left = mid + 1; // 오른쪽 범위로 이동
+      }
+    }
+    // 오른쪽 절반이 정렬되어 있는 경우
+    else {
+      if (nums[mid] < target && target <= nums[right]) {
+        left = mid + 1; // 오른쪽 범위로 이동
+      } else {
+        right = mid - 1; // 왼쪽 범위로 이동
+      }
+    }
+  }
+
+  return -1;
+};