diff --git a/.vscode/tasks.json b/.vscode/tasks.json
index a5beda6..79b3f79 100644
--- a/.vscode/tasks.json
+++ b/.vscode/tasks.json
@@ -70,13 +70,22 @@
             "type": "cppbuild",
             "label": "C/C++: gcc.exe 활성 파일 빌드",
             "command": "C:/mingw64/bin/gcc.exe",
+            // main 다수 (테스트)
             "args": [
                 "-fdiagnostics-color=always",
                 "-g",
-                "${fileDirname}\\*.c",
+                "${file}",
                 "-o",
-                "${fileDirname}\\bin\\${fileBasenameNoExtension}.exe"
+                "${fileDirname}\\bin\\${fileBasenameNoExtension}.exe",
             ],
+            // // main 단일 프로젝트
+            // "args": [
+            //     "-fdiagnostics-color=always",
+            //     "-g",
+            //     "${fileDirname}\\*.c",
+            //     "-o",
+            //     "${fileDirname}\\bin\\${fileBasenameNoExtension}.exe"
+            // ],
             "options": {
                 "cwd": "C:/mingw64/bin"
             },
diff --git a/practice/lc_functionArgsByReference.c b/practice/lc_functionArgsByReference.c
new file mode 100644
index 0000000..2e49360
--- /dev/null
+++ b/practice/lc_functionArgsByReference.c
@@ -0,0 +1,15 @@
+#include <stdio.h>
+
+void addone(int n)
+{
+    n++;
+}
+
+int main()
+{
+    int n = 0;
+    printf("Step0: %d\n", n);
+    addone(n);
+    printf("Step2: %d\n", n);
+
+}
\ No newline at end of file
diff --git a/practice/lc_structures.c b/practice/lc_structures.c
new file mode 100644
index 0000000..e07267c
--- /dev/null
+++ b/practice/lc_structures.c
@@ -0,0 +1,30 @@
+#include <stdio.h>
+
+struct Point
+{
+    int x;
+    int y;
+};
+
+typedef struct
+{
+    char* brand; // 동적 할당을 위한 처리
+    int model;
+} Vehicle;
+
+int main()
+{
+    struct Point pt;
+    pt.x = 10;
+    pt.y = 5;
+
+    Vehicle vc;
+    vc.brand = "Ford";
+    vc.model = 2025;
+
+    printf("pt.x: %d\n", pt.x);
+    printf("pt.y: %d\n", pt.y);
+    printf("\n");
+    printf("vc.brand: %s\n", vc.brand);
+    printf("vc.model: %d\n", vc.model);
+}
\ No newline at end of file