diff --git a/README.md b/README.md
index 02615d7..1af57ae 100644
--- a/README.md
+++ b/README.md
@@ -22,38 +22,21 @@ int main()
    
 }
 步骤2
-#include <iostream>
-
+#include<stdio.h>
 int main()
 {
-	struct student
+	int num[3];
+	float math[3],physic[3],english[3],sum[3];
+	int i;
+	for(i=0;i<3;i++)
 	{
-		int number;
-		float gaoshu;
-		float dawu;
-		float yy;
-		float add;
-	}student1, student2, student3;
-	scanf("%d",&student1.number);
-scanf("%f",&student1.gaoshu);
-scanf("%f",&student1.dawu);
-scanf("%f",&student1.yy);
-scanf("%d",&student2.number);
-scanf("%f",&student2.gaoshu);
-scanf("%f",&student2.dawu);
-scanf("%f",&student2.yy);
-scanf("%d",&student3.number);
-scanf("%f",&student3.gaoshu);
-scanf("%f",&student3.dawu);
-scanf("%f",&student3.yy);
-	student1.add = (student1.gaoshu + student1.dawu + student1.yy);
-	student2.add = (student2.gaoshu + student2.dawu + student2.yy);
-	student3.add = (student3.gaoshu + student3.dawu + student3.yy);
-	printf("%d  %f  %f  %f  %f\n", student1.number, student1.gaoshu, student1.dawu, student1.yy, student1.add);
-
-printf("%d  %f  %f  %f  %f\n", student2.number, student2.gaoshu, student2.dawu, student2.yy, student2.add);
-
-printf("%d  %f  %f  %f  %f\n", student3.number, student3.gaoshu, student3.dawu, student3.yy, student3.add);
+		scanf("%d %f %f %f",&num[i],&math[i],&physic[i],&english[i]);
+		sum[i]=math[i]+physic[i]+english[i];
+	}
+	for(i=0;i<3;i++)
+	{
+		printf("%d %.1f %.1f %.1f %.1f\n",num[i],math[i],physic[i],english[i],sum[i]);
+	}	
 }
 步骤3
 int main()
@@ -482,176 +465,172 @@ scanf("%d",&changer1);
 }
 步骤八
 #include<stdio.h>
-struct student{
-	int id;
-	int  class;
+#include<string.h> 
+#define N 100
+
+struct stu_info
+{
+	char num[20];
+	char cls[20];
 	char name[20];
-	double score1;
-	double score2;
-	double score3;
-	double score;
-}stu[7];
-void xunwen(void){
+	float math,physics,english,total;
+};
+
+struct stu_info stu[N];
+int top=0;
+
+void print_menu()
+{
 	printf("1.input\n");
-	printf("2.delet\n");
+	printf("2.delete\n");
 	printf("3.select\n");
 	printf("4.order\n");
 	printf("5.output\n");
 	printf("6.quit\n");
 	printf("please input your option\n");
 }
-void input(void){
-	 int i,j;
-	 char str[3];
-	 void zhixing(void);
-	 for(i=0;i<7;i++){
-	 		printf("id ");
-	 		scanf("%d",&stu[i].id);
-	 		printf("class ");
-	 		scanf("%d",&stu[i].class);
-	 		printf("name ");
-	 		scanf("%s",stu[i].name);
-	 		printf("score1 ");
-	 		scanf("%lf",&stu[i].score1);
-	 		printf("score2 ");
-	 		scanf("%lf",&stu[i].score2);
-	 		printf("score3 ");
-	 		scanf("%lf",&stu[i].score3);
-	 		printf("continue?\n");
-	 		scanf("%s",str);
-	 		if(str[0]=='y')
-	 		continue;
-	 		else if(str[0]=='n')
-	 		break;
-	 		else
-			 return;
-	 }
-	 for(i=0;i<7;i++){
-	 	stu[i].score=stu[i].score1+stu[i].score2+stu[i].score3;
-	 }
-	 xunwen();
-	 zhixing();
-}
-void delet(struct student stu4[]){
-	void xunwen(void);
-	void zhixing(void);
-	 int i,j,k,a,b,c;
-	 char str[3];
-	 scanf("%d",&a);
-	 for(i=0;i<7;i++){
-	 	if(stu[i].id==a){
-          stu[i].id=0;
-		 }
-	 }
-	 for(i=0;i<7;i++){
-	 	if(stu[i].id!=0)
-	 	printf("%d %d %s %.1f %.1f %.1f %.1f %.1f\n",stu[i].id,stu[i].class,stu[i].name,stu[i].score1,stu[i].score2,stu[i].score3,stu[i].score);
-	 }
-	 printf("continue?\n");
-	 struct student *p=stu;
-	 scanf("%s",str);
-	 if(str[0]=='y')
-	 delet(p);
-	 else if(str[0]=='n')
-	 xunwen();
-	 zhixing();
+
+void print()
+{
+	int i;
+	for(i=0;i<top;i++) printf("%s,%s,%s,%.1f,%.1f,%.1f,%.1f\n",stu[i].num,stu[i].cls,stu[i].name,stu[i].math,stu[i].physics,stu[i].english,stu[i].total);
 }
-void select(struct student stu7[]){
-	 void xunwen(void);
-	 void zhixing(void);
-	 int i,j,k,a,b,c=1;
-	 char str[3];
-	 scanf("%d",&a);
-	 if(a>100){
-	 	for(i=0;i<7;i++){
-	 		if(stu7[i].id==a)
-	 		printf("%d %d %s %.1f %.1f %.1f %.1f\n",stu[i].id,stu[i].class,stu[i].name,stu[i].score1,stu[i].score2,stu[i].score3,stu[i].score);
-	 		c=0;
-		 }
-	 }
-	 else if(a<100){
-	 	for(i=0;i<7;i++){
-	 		if(stu7[i].class==a){
-	 				printf("%d %d %s %.1f %.1f %.1f %.1f\n",stu[i].id,stu[i].class,stu[i].name,stu[i].score1,stu[i].score2,stu[i].score3,stu[i].score);
-	 				c=0;
-			 }	
-	    }
-	 }
-	 if(c==1)
-	 printf("there is no eligible student");
-	 printf("continue?\n");
-	 struct student *p=stu;
-	 scanf("%s",str);
-	 if(str[0]=='y'){
-	 	select(p);
-	 }
-	 else if(str[0]=='n'){
-	 	xunwen();
-	 	zhixing();
-	 }
+
+void input()
+{
+	char op[20];
+	while(1)
+	{
+		printf("Id ");
+		scanf("%s",stu[top].num);
+		printf("class ");
+		scanf("%s",&stu[top].cls);
+		printf("name ");
+		scanf("%s",stu[top].name);
+		printf("score1 ");
+		scanf("%f",&stu[top].math);
+		printf("score2 ");
+		scanf("%f",&stu[top].physics);
+		printf("score3 ");
+		scanf("%f",&stu[top].english);
+		stu[top].total=stu[top].math+stu[top].physics+stu[top].english;
+		top++;
+		printf("continue?\n");
+		do{
+			scanf("%s",op);
+		}while(strcmp(op,"yes")!=0&&strcmp(op,"no")!=0);
+		if(strcmp(op,"no")==0) return;
+	}
 }
-void order(struct student stu2[]){
-	void zhixing(void);
-	void output(void);
-     int i,j,k=0,a,b,c;
-     struct student temp;
-     struct student stu1[7];
-     for(i=0;i<7;i++){
-     	stu1[i]=stu2[i];
-	 }
-	 for(i=0;i<6;i++){
-	 	for(j=i+1;j<7;j++){
-	 		if(stu1[j].score>=stu1[i].score){
-	 			temp=stu1[i];
-	 			stu1[i]=stu1[j];
-	 			stu1[j]=temp;
-			 }
-		 }
-	 }
-	 for(i=1;i<30;i++){
-	 	for(j=0;j<7;j++){
-	 		if(stu1[j].class==i)
-	 		stu2[k++]=stu1[j];
-		 }
-	 }
-	 for(i=0;i<7;i++){
-	 	if(stu[i].id!=0){
-	 		printf("%d %s %d %.1f %.1f %.1f",stu[i].id,stu[i].class,stu[i].name,stu[i].score1,stu[i].score2,stu[i].score3);
-		 }
-	 } 
-	 xunwen();
-	 zhixing();
+
+void del()
+{
+	int i,d;
+	char key[20],op[20];
+	while(1)
+	{
+		i=0,d=0;
+		scanf("%s",key);
+		while(i<top)
+		{
+			if(strcmp((stu+i)->num,key)==0||strcmp((stu+i)->name,key)==0)
+			{
+				d++;top--;
+				*(stu+i)=*(stu+i+d);
+			}
+			else
+			{
+				*(stu+i)=*(stu+i+d);
+				i++;
+			}
+		}
+		print();
+		printf("continue?\n");
+		do{
+			scanf("%s",op);
+		}while(strcmp(op,"yes")!=0&&strcmp(op,"no")!=0);
+		if(strcmp(op,"no")==0) return;
+	}
 }
-void output(){
-	void zhixing(void);
-	int i;
-	for(i=0;i<7;i++){
-		if(stu[i].id!=0)
-			printf("%d %d %s %.1f %.1f %.1f %.1f\n",stu[i].id,stu[i].class,stu[i].name,stu[i].score1,stu[i].score2,stu[i].score3,stu[i].score);
+
+void select()
+{
+	int i,flag;
+	char key[20],op[20];
+	while(1)
+	{
+		flag=0;
+		scanf("%s",key);
+		for(i=0;i<top;i++)
+		{
+			if(strcmp((stu+i)->num,key)==0||strcmp((stu+i)->cls,key)==0)
+			{
+				flag=1;
+				printf("%s,%s,%s,%.1f,%.1f,%.1f,%.1f\n",stu[i].num,stu[i].cls,stu[i].name,stu[i].math,stu[i].physics,stu[i].english,stu[i].total);
+			}
+		}
+		if(!flag)
+		{
+			printf("there is no eligible student\n");
+			return;
+		}
+		printf("continue?\n");
+		do{
+			scanf("%s",op);
+		}while(strcmp(op,"yes")!=0&&strcmp(op,"no")!=0);
+		if(strcmp(op,"no")==0) return;
 	}
-	xunwen();
-	zhixing();
 }
-void quit(void){
-	return;
-} 
-void zhixing(void){
-	int i;
-	scanf("%d",&i);
-	struct student *p=stu;
-	 switch(i){
-    	case 1:input();break;
-    	case 2:delet(p);break;
-    	case 3:select(p);break;
-    	case 4:order(p);break;
-    	case 5:output();break;
-    	case 6:quit();break;
+
+void order()
+{
+	int i,j;
+	struct stu_info tmp;
+	for(i=0;i<top;i++)
+	{
+		for(j=0;j<top-i-1;j++)
+		{
+			if(strcmp((stu+j)->cls,(stu+j+1)->cls)==1||strcmp((stu+j)->cls,(stu+j+1)->cls)==0&&((stu+j)->total<(stu+j+1)->total))
+			{
+				tmp = *(stu+j);
+				*(stu+j) = *(stu+j+1);
+				*(stu+j+1) = tmp;
+			} 
+		}
 	}
+	print();
+	return;
 }
-int main(){
-	xunwen();
-	zhixing();
-	return 0;
+
+int main()
+{
+	int op;
+	while(1)
+	{
+		print_menu();
+		scanf("%d",&op);
+		switch(op)
+		{
+			case(1):
+				input();
+				break;
+			case(2):
+				del();
+				break;
+			case(3):
+				select();
+				break;
+			case(4):
+				order();
+				break;
+			case(5):
+				print();
+				break;
+			case(6):
+				return 0;
+        }
+    }
 }
 
+