diff --git a/.vscode/tasks.json b/.vscode/tasks.json
new file mode 100644
index 0000000..2f304eb
--- /dev/null
+++ b/.vscode/tasks.json
@@ -0,0 +1,28 @@
+{
+    "tasks": [
+        {
+            "type": "cppbuild",
+            "label": "C/C++: cl.exe 활성 파일 빌드",
+            "command": "cl.exe",
+            "args": [
+                "/Zi",
+                "/EHsc",
+                "/nologo",
+                "/Fe${fileDirname}\\${fileBasenameNoExtension}.exe",
+                "${file}"
+            ],
+            "options": {
+                "cwd": "${fileDirname}"
+            },
+            "problemMatcher": [
+                "$msCompile"
+            ],
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            },
+            "detail": "디버거에서 생성된 작업입니다."
+        }
+    ],
+    "version": "2.0.0"
+}
\ No newline at end of file
diff --git a/w1/README.md b/w1/README.md
index 92e5ce4..9c9e7fe 100644
--- a/w1/README.md
+++ b/w1/README.md
@@ -1 +1,4 @@
 여기에 1주차 과제를 작성해주시면 됩니다!
+
+
+2-1 자료구조 강의를 정복하기 위한 지식을 배우고 싶습니다.
\ No newline at end of file
diff --git a/w1/test.exe b/w1/test.exe
new file mode 100644
index 0000000..561893a
Binary files /dev/null and b/w1/test.exe differ
diff --git a/w1/test.ilk b/w1/test.ilk
new file mode 100644
index 0000000..8edfd9f
Binary files /dev/null and b/w1/test.ilk differ
diff --git a/w1/test.obj b/w1/test.obj
new file mode 100644
index 0000000..8e2f153
Binary files /dev/null and b/w1/test.obj differ
diff --git a/w1/test.pdb b/w1/test.pdb
new file mode 100644
index 0000000..5797615
Binary files /dev/null and b/w1/test.pdb differ
diff --git a/w1/vc140.pdb b/w1/vc140.pdb
new file mode 100644
index 0000000..da2723d
Binary files /dev/null and b/w1/vc140.pdb differ
diff --git a/w2/w2.cpp b/w2/w2.cpp
index e69de29..26bc884 100644
--- a/w2/w2.cpp
+++ b/w2/w2.cpp
@@ -0,0 +1,77 @@
+#include<iostream>
+#include<string>
+using namespace std;
+
+class Stack {
+private:
+	int* arr;
+	int top;
+	int size;
+public:
+	Stack(int size)
+		: size{ size }, top{ -1 } {
+		arr = new int[size];
+	}
+	~Stack() {
+		delete[] arr;
+	}
+	void push(int x) {
+		if (top + 1 < size) {
+			arr[++top] = x;
+		}
+		else {
+			cout << "용량 초과";
+			return;
+		}
+	}
+	int pop() {
+		if (empty()) {
+			return -1;
+		}
+		else {
+			return arr[top--];
+		}
+	}
+	int gettop() const {
+		if (empty()) {
+			return -1;
+		}
+		else {
+			return arr[top];
+		}
+	}
+	bool empty() const {
+		if (top == -1)
+			return 1;
+		else
+			return 0;
+	}
+	int getsize() const {
+		return top + 1;
+	}
+};
+void stackc(string fun,Stack& stack) {
+	if (fun == "push") {
+		int x;
+		cin >> x;
+		stack.push(x);
+	}
+	else if (fun == "top")
+		cout<<stack.gettop()<<endl;
+	else if (fun == "pop")
+		cout << stack.pop() << endl;
+	else if (fun == "empty")
+		cout << stack.empty() << endl;
+	else if (fun == "size")
+		cout << stack.getsize() << endl;
+}
+int main() {
+	int x;
+	cin >> x;
+	Stack stack(x);
+	for (int i = 0; i < x; i++) {
+		string y;
+		cin >> y;
+		stackc(y, stack);
+	}
+}
\ No newline at end of file
diff --git a/w4/w4.cpp b/w4/w4.cpp
index e69de29..96e712e 100644
--- a/w4/w4.cpp
+++ b/w4/w4.cpp
@@ -0,0 +1,86 @@
+#include<iostream>
+using namespace std;
+
+class Node
+{
+public:
+    char data;
+    Node* parent;
+    Node* right;
+    Node* left;
+
+    Node();
+    Node(char data) : data{ data }, parent{ nullptr }, right{ nullptr }, left{ nullptr } {}
+    ~Node() {
+        delete right;
+        delete left;
+    }
+    void addright(Node* x) {
+        right = x;
+        right->parent = this;
+        
+    }
+    void addleft(Node* x) {
+        left = x;
+        left->parent = this;
+    }
+};
+class Tree {
+private:
+    Node* root;
+public:
+    Tree() : root{ nullptr } {}
+    ~Tree() { delete root; }
+    Node* getroot() { return root; }
+    Node* findNode(Node* x, char y) {
+        if (x == nullptr) 
+            return nullptr;
+        if (x->data == y) 
+            return x;
+        Node* f = findNode(x->left, y);
+        if (f) 
+            return f;
+        return findNode(x->right, y);
+    }
+    void setTree(char a, char b, char c) {
+        if (root == nullptr) {
+            root = new Node(a);
+        }
+        Node* p = findNode(root, a);
+        if (b != '.') p->addleft(new Node(b));
+        if (c != '.') p->addright(new Node(c));
+    }
+    void preorder(Node* n) {
+        if (n == nullptr) return;
+        cout << n->data;
+        preorder(n->left);
+        preorder(n->right);
+    }
+    void inorder(Node* n) {
+        if (n == nullptr) return;
+        inorder(n->left);
+        cout << n->data;
+        inorder(n->right);
+    }
+    void postorder(Node* n) {
+        if (n == nullptr) return;
+        postorder(n->left);
+        postorder(n->right);
+        cout << n->data;
+    }
+};
+
+int main() {
+    int n;
+    cin >> n;
+    Tree tree;
+    for (int i = 0; i < n; i++) {
+        char a, b, c;
+        cin >> a >> b >> c;
+        tree.setTree(a, b, c);
+    }
+    Node* root = tree.getroot();
+    tree.preorder(root); cout << endl;
+    tree.inorder(root); cout << endl;
+    tree.postorder(root); cout << endl;
+}
\ No newline at end of file