diff --git a/Cprogramming/2dim_array.c b/Cprogramming/2dim_array.c
new file mode 100644
index 00000000..0d4170a6
--- /dev/null
+++ b/Cprogramming/2dim_array.c
@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+int main() {
+    //in c programming language, 2dim arrary is in row
+    // ini
+    //int a[5][3] = {{},{},{}} 分段赋值
+    //int a[5][3] = {} 按行连续赋值
+    //如果对全部元素赋值，第一维的长度可以不给出 如下
+    int a[3][3] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
+    int b[][3] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
+    
+
+    return 0;
+}
\ No newline at end of file
diff --git a/Cprogramming/2dim_array_pointer b/Cprogramming/2dim_array_pointer
new file mode 100755
index 00000000..e0fb699b
Binary files /dev/null and b/Cprogramming/2dim_array_pointer differ
diff --git a/Cprogramming/2dim_array_pointer.c b/Cprogramming/2dim_array_pointer.c
new file mode 100644
index 00000000..4fea39c2
--- /dev/null
+++ b/Cprogramming/2dim_array_pointer.c
@@ -0,0 +1,16 @@
+#include <stdio.h>
+
+int main() {
+    int a[3][4] = {{0,1,2,3}, {4, 5, 6, 7}, {8, 9, 10, 11}};
+    int(*p)[4] = a;
+//一个指向数组的指针p，数组的类型为int[4]
+    printf("%d\n", sizeof(*(p+1))); // 16 that is because 4 * 4 = 16
+
+    /**
+     *     *(p+1)单独使用表示第一行数据，放在表达式里就代表第一行数据的首地址
+     *     *(p+1)+1 代表第一行数据的第1个元素的地址
+     *     *(*(p+1)+1) 代表第一行数据的第一个元素
+    */
+
+    return 0;
+}
\ No newline at end of file
diff --git a/Cprogramming/a.out b/Cprogramming/a.out
new file mode 100755
index 00000000..547ff1ce
Binary files /dev/null and b/Cprogramming/a.out differ
diff --git a/Cprogramming/array_ini.c b/Cprogramming/array_ini.c
new file mode 100644
index 00000000..cc482107
--- /dev/null
+++ b/Cprogramming/array_ini.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+
+int main() {
+
+    int a[4] = {20, 1, 2, 3}; // directly
+    int a[10] = {1, 2, 3, 4, 5}; //partly
+
+    int a[] = {1, 3, 4, 5, 6}; // == int a[5] = {1, 3, 4, 5, 6}
+
+    
+
+    return 0;
+}
\ No newline at end of file
diff --git a/Cprogramming/ball b/Cprogramming/ball
new file mode 100755
index 00000000..a379443b
Binary files /dev/null and b/Cprogramming/ball differ
diff --git a/Cprogramming/ballGame b/Cprogramming/ballGame
new file mode 100755
index 00000000..0ca88b9f
Binary files /dev/null and b/Cprogramming/ballGame differ
diff --git a/Cprogramming/ballGame.c b/Cprogramming/ballGame.c
new file mode 100644
index 00000000..212cdda3
--- /dev/null
+++ b/Cprogramming/ballGame.c
@@ -0,0 +1,96 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h> 
+
+/**
+ * 1. 尝试不用usleep函数 利用循环语句使小球变慢
+ * 2. 尝试用printf("\a") 实现触边界响铃效果
+ * 3. 尝试绘制边框
+ * 
+ * 参考答案链接：https://blog.csdn.net/weixin_72939806/article/details/129221682
+*/
+
+int main() {
+    
+    
+    // 静止小球的位置 
+    int i, j;
+    int x = 2; //坐标
+    int y = 2;
+
+    int velocity_x = 1;
+    int velocity_y = 1;
+    int left = 0;
+    int right = 20;
+    int top = 0;
+    int bottom = 10;
+    //长10 宽20
+
+  
+
+    //int height = 20;
+    //int velocity = 1;
+    // printf "\033c" 清屏
+    // 小球下落： 让小球的x坐标增加
+    // 上下弹跳的小球：小球新位置 = 旧位置x + 速度velocity，当判断小球到达上下边界时改变方向，即改变velocity符号
+    // 斜着弹跳的小球：增加x，y两个方向的速度
+
+
+   while(1){
+		x+=velocity_x;
+		y+=velocity_y;
+		
+		system("clear");
+		
+		for(j=0;j<=right;j++) printf("_"); printf("\n");
+		for(i=1;i<bottom;i++){
+			printf("|");
+			for(j=0;j<right-1;j++) printf(" ");
+			printf("|\n"); 
+		}
+		for(j=0;j<=right;j++) printf("=");
+        
+		printf("\033[0;0H");
+		
+		for(i=0;i<x;i++)
+			printf("\n");
+		for(j=0;j<y;j++){
+			if(j==0)printf("|");
+			else printf(" ");
+		}
+		printf("o");
+		printf("\n");
+		usleep(250000);
+		 
+		if(x==top+1||x==bottom-1){
+			velocity_x=-velocity_x;
+			printf("\a");
+		}
+		if(y==left+1||y==right-1){
+			velocity_y=-velocity_y;
+			printf("\a");
+		}
+	}
+
+
+
+// for(x=1; x < 10; x++) {
+//     system("clear");
+
+//     for (i=0; i < x; i++) {
+//         printf("\n");
+//     }
+
+//     for (j = 0; j < y; j++) {
+//         printf(" ");
+//     }
+
+//     printf("o");
+//     printf("\n");
+//     //sleep(1);
+//     usleep(200000); // 500毫秒 * 1000 微秒/毫秒 = 500000 微秒
+// }
+
+
+    return 0;
+}
\ No newline at end of file
diff --git a/Cprogramming/char_array.c b/Cprogramming/char_array.c
new file mode 100644
index 00000000..e6b5b0d7
--- /dev/null
+++ b/Cprogramming/char_array.c
@@ -0,0 +1,15 @@
+#include <stdio.h>
+
+int main() {
+    //字符数组实际上就是一系列字符的集合也就是字符串 
+    char str[30] = {"asdasdasdasdasdasd"};
+    char str[20] = "asdasdasasfs";
+
+    char str[] = "fefegfef";
+
+    //字符数组只有在定义的时候可以一整个字符串一次性赋值给他，一旦定义完了，就只能一个字符一个字符地赋值了
+
+    
+
+    return 0;
+}
\ No newline at end of file
diff --git a/Cprogramming/end_of_string b/Cprogramming/end_of_string
new file mode 100755
index 00000000..556abb78
Binary files /dev/null and b/Cprogramming/end_of_string differ
diff --git a/Cprogramming/end_of_string.c b/Cprogramming/end_of_string.c
new file mode 100644
index 00000000..828979e8
--- /dev/null
+++ b/Cprogramming/end_of_string.c
@@ -0,0 +1,17 @@
+#include <stdio.h>
+//局部变量的初始值不一定全是0
+
+int main() {
+    char str[30];
+    char c;
+    int i;
+    for (c = 65, i = 0; c <= 90; c++, i++) {
+        str[i] = c;
+    }
+    str[i] = 0; //也可以写作str[i] = '\0'手动结束字符串 
+    //更专业的做法是 将str初始就全为0 str = {0};
+
+    
+    printf("%s\n", str);
+    return 0;
+}
\ No newline at end of file
diff --git a/Cprogramming/func_pointer b/Cprogramming/func_pointer
new file mode 100755
index 00000000..ff9a0101
Binary files /dev/null and b/Cprogramming/func_pointer differ
diff --git a/Cprogramming/func_pointer.c b/Cprogramming/func_pointer.c
new file mode 100644
index 00000000..be6afea5
--- /dev/null
+++ b/Cprogramming/func_pointer.c
@@ -0,0 +1,20 @@
+#include <stdio.h>
+
+int max(int a, int b) {
+    return a>b ? a : b;
+}
+
+int main() {
+    int x, y, maxval;
+
+    int (*pmax)(int, int) = max;
+    //函数指针
+
+    printf("input two numbers:");
+    scanf("%d %d", &x, &y);
+    maxval = (*pmax)(x,y);
+    printf("Max value: %d\n", maxval);
+
+
+    return 0;
+}
\ No newline at end of file
diff --git a/Cprogramming/gets_scanf.c b/Cprogramming/gets_scanf.c
new file mode 100644
index 00000000..cd6db9fb
--- /dev/null
+++ b/Cprogramming/gets_scanf.c
@@ -0,0 +1,10 @@
+#include <stdio.h>
+
+int main() {
+    //gets  可以接受带空格的字符串
+    //scanf 不行,but 不是完全不行
+    
+    
+
+    return 0;
+}
\ No newline at end of file
diff --git a/Cprogramming/hello_world.c b/Cprogramming/hello_world.c
new file mode 100644
index 00000000..38759a0d
--- /dev/null
+++ b/Cprogramming/hello_world.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int main() {
+
+    printf("Hello world");
+
+    return 0;
+}
\ No newline at end of file
diff --git a/Cprogramming/last_skill_pointer.c b/Cprogramming/last_skill_pointer.c
new file mode 100644
index 00000000..e2ca44e5
--- /dev/null
+++ b/Cprogramming/last_skill_pointer.c
@@ -0,0 +1,19 @@
+#include <stdio.h>
+
+int main() {
+    /**
+     * int *p1[6]; 指针数组
+     * int *(p2[6]); 指针数组
+     * int (*p3)[6]; 二维数组指针
+     * int (*p4)(int, int); 函数指针
+     * 
+    */
+
+   //c语言标准规定，对于一个符号的定义，编译器总是从**它的名字**开始读，然后按照优先级顺序依次解析
+   //优先级顺序： 定义中被括号()扩起的,
+   //           后缀操作：（）表示这是一个函数，[] 表示这是一个数组
+   //           前缀操作： *  表示指向xxx的指针
+
+    
+    return 0;
+}
\ No newline at end of file
diff --git a/Cprogramming/main_advanced b/Cprogramming/main_advanced
new file mode 100755
index 00000000..74e27b86
Binary files /dev/null and b/Cprogramming/main_advanced differ
diff --git a/Cprogramming/main_advanced.c b/Cprogramming/main_advanced.c
new file mode 100644
index 00000000..98d8f6a2
--- /dev/null
+++ b/Cprogramming/main_advanced.c
@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+
+int main(int argc, char *argv[]) {
+    //argc表示传递的字符串的数目，argv是一个指针数组，每一个指针指向一个字符串
+
+    int i;
+    printf("The program receives %d parameters:\n", argc);
+    for (i=0; i<argc; i++) {
+        printf("%s\n", argv[i]);
+    }
+
+    return 0;
+}
\ No newline at end of file
diff --git a/Cprogramming/memory_leak.c b/Cprogramming/memory_leak.c
new file mode 100644
index 00000000..00857e86
--- /dev/null
+++ b/Cprogramming/memory_leak.c
@@ -0,0 +1,10 @@
+#include <stdlib.h>
+#include <stdio.h>
+
+int main() {
+    while(1) {
+        malloc(1024); // allocate 1024bytes
+    }
+
+    return 0;
+}
\ No newline at end of file
diff --git a/Cprogramming/non-blockingListen b/Cprogramming/non-blockingListen
new file mode 100755
index 00000000..ebc99930
Binary files /dev/null and b/Cprogramming/non-blockingListen differ
diff --git a/Cprogramming/non-blockingListen.c b/Cprogramming/non-blockingListen.c
new file mode 100644
index 00000000..e69de29b
diff --git a/Cprogramming/passw b/Cprogramming/passw
new file mode 100755
index 00000000..7b848dc0
Binary files /dev/null and b/Cprogramming/passw differ
diff --git a/Cprogramming/passw.c b/Cprogramming/passw.c
new file mode 100644
index 00000000..cad76189
--- /dev/null
+++ b/Cprogramming/passw.c
@@ -0,0 +1,48 @@
+#include <stdio.h>
+#include <ctype.h>
+#include <stdlib.h>
+#define PWDLEN 20
+
+void getpwd(char *pwd, int pwdlen);
+
+int main()
+{
+    char pwd[PWDLEN + 1];
+    printf("Input password: ");
+    getpwd(pwd, PWDLEN);
+    system("stty echo");
+    printf("The password is: %s\n", pwd);
+    
+    return 0;
+}
+
+/**
+ * get the password by users
+ * @param pwd char* 保存密码的内存的首地址
+ * @param pwdlen int 密码的最大长度
+*/
+
+void getpwd(char *pwd, int pwdlen) {
+    char ch = 0;
+    int i = 0;
+    system("stty -echo");//取消回显
+    while (i < pwdlen) { //循环输入密码
+        ch = getchar(); 
+        if (ch == '\n') { //unix敲入回车结束
+            //printf("\n");
+            break;
+        }
+
+        if (ch == '\b' && i > 0) {//删除键回退之后覆盖
+            i--;
+            //printf("\b \b");
+        } else if (isprint(ch)) {
+            pwd[i] = ch;
+            //printf("*");
+            i++;
+        }
+    }
+    pwd[i] = 0; //最后结束
+    printf("\n");
+    //system("stty echo");
+}
\ No newline at end of file
diff --git a/Cprogramming/pointer.c b/Cprogramming/pointer.c
new file mode 100644
index 00000000..9130b6b5
--- /dev/null
+++ b/Cprogramming/pointer.c
@@ -0,0 +1,29 @@
+/**
+ * Notes on Pointer Full
+ * 1. 定义指针变量：
+ * datatype *name 指针变量所指向的数据类型 指针变量的名字
+ * 
+ * 2.关于*和&的谜题：
+ * int a； pa是指向它的指针
+ * 2.1 *&a是什么意思？ 
+ *  attempt：*（&a） == a
+ * 2.2 &*pa是什么意思？
+ *  attempt： == pa
+ * 
+ * 3.数组指针
+ * 3.1 *p++ = *（p++）
+ * 3.2 *++p = *（++p）
+ * 
+ * 
+ * 4.数组和指针不等价
+ * 
+*/
+
+#include <stdio.h>
+
+int main() {
+
+    
+
+    return 0;
+}
\ No newline at end of file
diff --git a/Cprogramming/problem_pointer b/Cprogramming/problem_pointer
new file mode 100755
index 00000000..2735e0e0
Binary files /dev/null and b/Cprogramming/problem_pointer differ
diff --git a/Cprogramming/problem_pointer.c b/Cprogramming/problem_pointer.c
new file mode 100644
index 00000000..915ddf8b
--- /dev/null
+++ b/Cprogramming/problem_pointer.c
@@ -0,0 +1,46 @@
+#include <stdio.h>
+
+int main() {
+    char *lines[5]= {
+        "COSC1283/1284",
+        "Programming",
+        "Techniques",
+        "is",
+        "great fun"
+    };
+    /**
+     * 实际上上述的字符串数组等同于:
+     * char *string0 = "C0SC1283/1284"
+     * char *string1 = "Programming"
+     * char *string2 = "Techniques"
+     * char *string3 = "is"
+     * char *string4 = "great fun"
+     * 
+     * char *lines[5];
+     * lines[0] = string0;
+     * lines[1] = string1;
+     * ....
+     * 
+     *  char* lines[5] 定义了一个指针数组
+    */
+
+    char *str1 = lines[1];
+    //attempt: str1存放着"COSC1283/1284"的首地址
+    char *str2 = *(lines + 3);
+    //att: str2存放着“is”的首地址
+    char c1 = *(*(lines + 4) + 6);
+    //att: c1 = 'f'
+    char c2 = (*lines + 5)[5];
+    //att: c2 = 
+    char c3 = *lines[0] + 2;
+    //att: c3 = 'C'
+
+    printf("str1 = %s\n", str1);
+    printf("str2 = %s\n", str2);
+    printf(" c1=%c\n",c1);
+    printf(" c2=%c\n",c2);
+    printf(" c3=%c\n",c3);
+
+    return 0;
+
+}
\ No newline at end of file
diff --git a/Cprogramming/scanf_advanceUsage.c b/Cprogramming/scanf_advanceUsage.c
new file mode 100644
index 00000000..e69de29b
diff --git a/conio.h b/conio.h
new file mode 160000
index 00000000..70935b61
--- /dev/null
+++ b/conio.h
@@ -0,0 +1 @@
+Subproject commit 70935b61efce6da9042f3543add106e7dc52e3ca