some programs!

CMakeLists.txt

@@ -1,9 +1,13 @@
 cmake_minimum_required(VERSION 3.10)
-project(exercises)
+project(exercises C CXX)
+
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_C_STANDARD_REQUIRED ON)
 
 set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
-file(GLOB_RECURSE SOURCES "*.cpp")
+file(GLOB_RECURSE SOURCES "*.cpp" "*.c")
 
 foreach (source ${SOURCES})
     # 获取源文件所在目录（绝对路径）
@@ -22,7 +26,7 @@ foreach (source ${SOURCES})
     endif ()
 
     add_executable(${target_name} ${source})
-    # 顺便把可执行文件输出到与源文件对应的目录中（可选）
+    # 把可执行文件输出到与源文件对应的目录中
     set_target_properties(${target_name} PROPERTIES
             RUNTIME_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/${rel_dir}"
     )