diff --git a/C++_level1/queque.cpp b/C++_level1/queque.cpp
new file mode 100644
index 00000000..c5e8d36c
--- /dev/null
+++ b/C++_level1/queque.cpp
@@ -0,0 +1,87 @@
+#include <iostream>
+using namespace std;
+typedef int Data_type;
+
+struct Linked_list
+{
+	Data_type data;
+	Linked_list * next;
+};
+			
+class Queue
+{
+public:
+	Queue() : head(0),tail(0),num(0) {}
+	void append (Data_type date);
+	Data_type pop();
+	bool is_full() { return num >= Max_num; }
+	bool is_empty() { return num <= 0; }
+private:
+	enum { Max_num = 100 };
+	Linked_list *head,*tail;
+	int num;
+};
+
+
+void Queue::append(Data_type data)
+{
+	if(is_full())
+	{
+		cerr << "Fail to append, Queue is full!\n";
+		return;
+	}
+	if(is_empty())
+	{
+		head = tail = new Linked_list;
+	}
+	else
+	{
+		tail = tail->next = new Linked_list;
+	}
+	tail->data = data;
+	tail->next = 0;
+	num++;
+}
+
+Data_type Queue::pop()
+{
+	if(is_empty())
+	{
+		cerr << "Fail to pop, Queue is empty!\n"; 
+		return -1;
+	}
+	Data_type data = head->data;
+	Linked_list *tmp = head;
+	head = head->next;
+	delete tmp;
+	num--;
+	return data;
+}
+
+
+
+int main()
+{
+	Queue q;
+	q.append(1);
+	q.append(2);
+	q.append(3);
+	int data = q.pop();
+	cout <<  noskipws      <<   data << endl;
+	 data = q.pop();
+	cout <<  noskipws      <<   data << endl;
+	 data = q.pop();
+	cout <<  noskipws      <<   data << endl;
+	 data = q.pop();
+	cout <<  noskipws      <<   data << endl;
+
+	for(int i = 0; i < 100; i++)
+	{
+		q.append(i);
+	}
+	q.append(1);
+	q.append(1);
+	return 0;
+}
+	
+	
diff --git a/C++_level1/stack.cpp b/C++_level1/stack.cpp
new file mode 100644
index 00000000..545bea99
--- /dev/null
+++ b/C++_level1/stack.cpp
@@ -0,0 +1,60 @@
+#include <iostream>
+using namespace std;
+typedef int Data_type;
+class Stack
+{
+public:
+	Stack() : i(-1) {}
+	void push(Data_type data)
+	{
+		if(is_full())
+		{
+			cerr << "Fail to push, Stack is full!\n";
+			return;
+		}
+		arr[++i] = data;
+	}	
+	Data_type pop()
+	{
+		if(is_empty())
+		{
+			cerr << "Fail to pop, Stack is empty\n";
+			return (-1);
+		}
+		return arr[i--];
+	}
+	bool is_full() { return (i >= Size - 1); }
+	bool is_empty() { return (i < 0); }
+private:
+	enum { Size = 100 };
+	int i;
+	Data_type arr[Size];
+};
+
+
+int main()
+{
+	
+	Stack s;
+	s.push(1);
+	s.push(2);
+	s.push(3);
+	int data = s.pop();
+	cout <<  noskipws      <<   data << endl;
+	 data = s.pop();
+	cout <<  noskipws      <<   data << endl;
+	 data = s.pop();
+	cout <<  noskipws      <<   data << endl;
+	 data = s.pop();
+	cout <<  noskipws      <<   data << endl;
+
+	for(int i = 0; i < 100; i++)
+	{
+		s.push(i);
+	}
+	s.push(1);
+	s.push(1);
+	return 0;
+}
+	
+	
diff --git a/level1/0runningLetter.c b/level1/0runningLetter.c
new file mode 100644
index 00000000..ce3d085e
--- /dev/null
+++ b/level1/0runningLetter.c
@@ -0,0 +1,28 @@
+#include <stdio.h>
+#include <unistd.h>
+#define COLUMN 80 
+
+int main(){
+	int blank,location;
+
+	for (location = 1; location <=COLUMN ; location++){
+		for (blank=1; blank < location; blank++){
+			printf(" ");
+		}
+		putchar('A');
+		usleep(2000000);
+		system("clear");
+	}
+	for (location = location-1; location >=1; location--){
+		for (blank=1; blank < location; blank++){
+			printf(" ");
+		}
+		putchar('A');
+		usleep(200000);
+		system("clear");
+	}
+	return 0;
+}
+
+		
+		
diff --git a/level1/Diophantus.c b/level1/Diophantus.c
new file mode 100644
index 00000000..27244525
--- /dev/null
+++ b/level1/Diophantus.c
@@ -0,0 +1,12 @@
+#include <stdio.h>
+
+int main()
+{
+	int x;
+	for(x=1; x<150; x++){
+		if(x/6 + x/12 + x/7 + 5 + x/2 + 4 ==x)  
+			break;
+	}
+	printf("The father had lived for %d years.\n",x);
+	return 0;
+}
diff --git a/level1/Goldbach.c b/level1/Goldbach.c
new file mode 100644
index 00000000..bd865ae7
--- /dev/null
+++ b/level1/Goldbach.c
@@ -0,0 +1,30 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+
+int isPrime(int x)
+{
+	int i;
+	int dlm = sqrt((double)x);
+
+	for (i=2; i<=dlm; i++)
+	{	if (x%i==0) break; }
+	if (x==1) return 0;
+	else if (x==2 || x==3 || i>dlm)
+	{	return 1; }
+	else return 0;
+	return 0;
+}
+
+int main()
+{
+	int i,j;
+
+	for (i=4; i<=100; i=i+2)
+	{	for (j=2; j<=i/2; j++)
+		{	if (isPrime(j) && isPrime(i-j))
+			{	printf("\n%d = prime%d + prime%d.",i,j,i-j);
+				break; }	}	}
+	return 0;
+}	
+	
diff --git a/level1/allPrime.c b/level1/allPrime.c
new file mode 100644
index 00000000..de34c762
--- /dev/null
+++ b/level1/allPrime.c
@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <math.h>
+#include <time.h>
+
+int main()
+{
+	int i,j; 
+	long begin,end;
+	
+	begin = time(NULL);
+	printf("\nThe primes are:\n%-7d",2);
+	for (i=3; i<1000; i=i+2){
+		for (j=3; j<=(int)sqrt(i); j=j+2)
+			if (i%j == 0) break;
+		if (j > (int)sqrt(i) )  printf("%-7d",i);
+	}
+	end = time(NULL);
+	printf("\nThe begin time is: %d.",begin);
+	printf("\nThe end time is: %d.",end);
+	printf("\nThe total time is: %lf seconds.",(end-begin)/1000000.0);
+	return 0;
+}
diff --git a/level1/hanoi.c b/level1/hanoi.c
new file mode 100644
index 00000000..cb7eb38b
--- /dev/null
+++ b/level1/hanoi.c
@@ -0,0 +1,7 @@
+#include <stdio.h>
+#include <stdlib.h>
+void(
+
+int mian()
+{
+		
diff --git a/level1/isPrime.c b/level1/isPrime.c
new file mode 100644
index 00000000..23290ede
--- /dev/null
+++ b/level1/isPrime.c
@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <math.h>
+
+int main()
+{
+	int i,num;
+
+	printf("\nPlease enter a number: ");
+	scanf("%d",&num);
+	if (num == 2)
+		printf("\nIt's a prime.\n");
+	else{
+		for (i=2; i<=sqrt(num); i=i+2){
+			if (num % i==0){
+				printf("\nIt's not a prime.\n");
+				break;
+			}
+		}
+		if (i > sqrt(num))
+			printf("\nIt's a prime.\n");
+	}
+	return 0;
+}
diff --git a/level1/narcissus.c b/level1/narcissus.c
new file mode 100644
index 00000000..e4497908
--- /dev/null
+++ b/level1/narcissus.c
@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+int main()
+{
+	int i,ones,tens,hundreds;
+	for (i=100; i<1000; i++){
+		ones = i % 10;
+		tens = i/10 %10;
+		hundreds = i/100;
+		if (ones*ones*ones + tens*tens*tens + hundreds*hundreds*hundreds == i)
+			printf("%7d\n",i);
+	}
+	return 0;
+}
diff --git a/level1/runningLetter.c b/level1/runningLetter.c
new file mode 100644
index 00000000..4e32d400
--- /dev/null
+++ b/level1/runningLetter.c
@@ -0,0 +1,26 @@
+#include <stdio.h>
+#include <unistd.h>
+#define COLUMN 80 
+#define PAUSE  100000
+
+int main(){
+	int blank,location=1,back=0;
+
+	do
+	{	for (blank=1; blank<location; blank++)
+		{	printf(" "); }
+		puts("A");
+		usleep(PAUSE);
+		system("clear");
+		if (location==COLUMN) back=1;
+		if (!back) location++;
+		else location--;
+	}
+	while (location<=COLUMN && location>=1);	
+
+	return 0;
+
+}
+
+		
+		
diff --git a/level1_2/Goldbach.c b/level1_2/Goldbach.c
new file mode 100644
index 00000000..bd865ae7
--- /dev/null
+++ b/level1_2/Goldbach.c
@@ -0,0 +1,30 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+
+int isPrime(int x)
+{
+	int i;
+	int dlm = sqrt((double)x);
+
+	for (i=2; i<=dlm; i++)
+	{	if (x%i==0) break; }
+	if (x==1) return 0;
+	else if (x==2 || x==3 || i>dlm)
+	{	return 1; }
+	else return 0;
+	return 0;
+}
+
+int main()
+{
+	int i,j;
+
+	for (i=4; i<=100; i=i+2)
+	{	for (j=2; j<=i/2; j++)
+		{	if (isPrime(j) && isPrime(i-j))
+			{	printf("\n%d = prime%d + prime%d.",i,j,i-j);
+				break; }	}	}
+	return 0;
+}	
+	
diff --git a/level1_2/a.out b/level1_2/a.out
new file mode 100755
index 00000000..49af0920
Binary files /dev/null and b/level1_2/a.out differ
diff --git a/level1_2/encryptDecrept b/level1_2/encryptDecrept
new file mode 100755
index 00000000..128cd18f
Binary files /dev/null and b/level1_2/encryptDecrept differ
diff --git a/level1_2/encryptDecrept.c b/level1_2/encryptDecrept.c
new file mode 100644
index 00000000..953d412a
--- /dev/null
+++ b/level1_2/encryptDecrept.c
@@ -0,0 +1,89 @@
+#include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#define MAXLINE 1000
+#define MAXPASSWD 100
+void encrypt(char text[]);
+void decrypt(char text[]);
+void getStr(char s[]);
+int equalStr(char s1[],char s2[]);
+/* <string.h> is required to use this function */
+
+int main()
+{	
+	int i;
+	char c;
+	char text[MAXLINE];
+	char passwd[MAXPASSWD];
+	char confirm[MAXPASSWD];
+
+	printf("\nEnter the text to be encrypt: ");
+	getStr(text);
+	do {
+	printf("\nEnter your password: ");
+	getStr(passwd);
+	printf("\nConfirm your password: ");
+	getStr(confirm);
+	if (equalStr(passwd,confirm))	break;	
+	printf("\nDifferent!\n");	}
+	while (1);
+
+	encrypt(text);
+
+	printf("\nWould you like to see your text after encrypt?\n");
+	puts("Press 'y' as yes.");
+	if ((c = getchar()) == 'y' || c == 'Y')
+	{	printf("%s\n",text);	}
+
+	getchar();
+	for (i = 3; i >= 1; i--)
+	{	puts("Enter your passward to decrypt your text: ");
+		getStr(confirm);
+		if (equalStr(passwd,confirm))	break;	
+		puts("Incorrect passward!");	}
+	if (i > 0)
+	{	decrypt(text);
+		printf("\n%s\n",text);	}
+	else	
+	{	puts("You've run out of three chances, bye!");	}
+}
+	
+
+
+void getStr(char s[])
+{	
+	int i;
+	for (i = 0; (s[i] = getchar()) != '\n'; i++)
+		;
+	s[i] = '\0';
+}
+
+
+
+int equalStr(char s1[],char s2[])
+{
+	assert(s1[0] != '\0');
+	int i;
+	if (strlen(s1) == strlen(s2))
+	{	for (i = 0; s1[i] != '\0'; i++) 
+		{	if (s1[i] != s2[i])	break;	}	}
+	if (s1[i] == '\0')	return 1;
+	else return 0;
+}
+
+
+
+void encrypt(char text[])
+{	
+	int i;
+	for (i = 0; text[i] != '\0'; i++)
+	{	text[i] = ~text[i];	}
+}
+
+
+
+void decrypt(char text[])
+{	
+	encrypt(text);	
+}
diff --git a/level1_2/hanoi.c b/level1_2/hanoi.c
new file mode 100644
index 00000000..cb7eb38b
--- /dev/null
+++ b/level1_2/hanoi.c
@@ -0,0 +1,7 @@
+#include <stdio.h>
+#include <stdlib.h>
+void(
+
+int mian()
+{
+		
diff --git a/level1_2/maze b/level1_2/maze
new file mode 100755
index 00000000..74416ac5
Binary files /dev/null and b/level1_2/maze differ
diff --git a/level1_2/maze.c b/level1_2/maze.c
new file mode 100644
index 00000000..026fcd45
--- /dev/null
+++ b/level1_2/maze.c
@@ -0,0 +1,70 @@
+/* Help the kid to go out of the maze. */
+
+#include <stdio.h>
+#define LINE 10
+#define COLM 10
+#define BEGINX 1
+#define BEGINY 1
+#define ENDX 8
+#define ENDY 9
+
+void drawMap(int kidx,int kidy,char map[LINE][COLM]);
+void go(int *kidx,int *kidy,char map[LINE][COLM]);
+
+/* 1 stands for wall,2 stands for way,and 0 stands for the kid. */
+char map[LINE][COLM]={ {1,1,1,1,1,1,1,1,1,1},
+                       {1,2,2,2,1,2,2,2,2,1},
+                       {1,2,1,2,1,2,1,1,2,1},
+                       {1,2,1,2,1,2,1,1,2,1},
+                       {1,2,2,2,2,2,2,1,2,1},
+                       {1,1,1,1,1,1,2,1,2,1},
+                       {1,2,2,2,2,2,2,1,2,1},
+                       {1,1,2,1,1,1,2,1,2,1},
+                       {1,2,2,2,1,1,2,1,2,2},
+                       {1,1,1,1,1,1,1,1,1,1}};
+
+
+int main()
+{	int kidx = BEGINX,kidy = BEGINY;
+	int success=0;
+
+	drawMap(kidx,kidy,map);
+	printf("\nPress 'W' to go top,\nPrese 'S' to go down,\nPress 'A' to go left,\nPress 'D' to go right.\n");
+	while (success!=1)
+	{	go(&kidx,&kidy,map);
+		drawMap(kidx,kidy,map);
+		if (kidx== ENDX&& kidy==ENDY) success=1;}
+		printf("\n ********************");
+		printf("\n * Congratulations! *");
+		printf("\n ********************\n");
+	return 0;
+}
+
+
+void drawMap(int kidx,int kidy,char map[LINE][COLM])
+{
+	int i,j;
+	putchar('\n');
+	map[kidx][kidy] = 0;
+	for (i=0; i<LINE; i++)
+	{	for (j=0; j<COLM; j++)
+		{	if (map[i][j]==1) putchar(35);
+			else if(map[i][j]==0) putchar(64);
+			else putchar(32);	}
+		putchar('\n');  }
+    map[kidx][kidy] = 2;
+	putchar('\n');
+}
+
+
+void go(int *x,int *y,char map[LINE][COLM])
+{
+	char c;
+	if (((c = getchar()) =='w' || c =='W') && map[*x-1][*y] == 2)	--*x;
+	else if ((c =='s' || c =='S') && map[*x+1][*y] == 2)	++*x;
+	else if ((c =='a' || c =='A') && map[*x][*y-1] == 2)	--*y;
+	else if ((c =='d' || c =='D') && map[*x][*y+1] == 2) 	++*y;
+	else puts("Invalid motion!");
+}
+
+
diff --git a/level1_2/t.c b/level1_2/t.c
new file mode 100644
index 00000000..70d87219
--- /dev/null
+++ b/level1_2/t.c
@@ -0,0 +1,11 @@
+#include <stdio.h>
+
+main()
+{
+	char str[10];
+	int i;
+	for (i = 0; i < 10; i++)	str[i] = getchar();
+	printf("\n%s\n",str);
+	for (i = 0; i < 10; i++)	putchar(str[i]);
+	putchar('\n');
+}