diff --git a/task5.cpp b/task5.cpp
new file mode 100644
index 0000000..ab43612
--- /dev/null
+++ b/task5.cpp
@@ -0,0 +1,189 @@
+#include <stdio.h>
+#include <string.h>
+
+#define MARK 10
+
+//定义结构体
+struct Student
+{
+	int ID;//学号 
+	int classes;
+	char name[8];
+	float math_grade;
+	float physics_grade;
+	float English_grade;
+	float sum;
+};
+
+//对结构体中的从start同学到end同学排序 
+void Sort(struct Student information[4],int start,int end)
+{
+	//先班级 
+	for(int i=start;i<=end;i++)
+	{
+		for(int j=start;j<=end-1;j++)
+		{
+			if(information[j].classes>information[j+1].classes)
+			{
+				struct Student tmp=information[j];
+				information[j]=information[j+1];
+				information[j+1]=tmp;
+			}
+		}
+	}
+	//同班同学再成绩 
+	for(int i=start;i<=end;i++)
+	 {
+	 	int con=0;//记录连续了几人 
+	 	for(int j=1;j<=end-i;j++)
+	 	{
+	 		if(information[i].classes==information[i+j].classes)
+	 		{con++;
+			 }
+			 else
+			 {
+			 break;
+			 }
+		 }
+			 
+		 if(con)//有人是同班同学，在此内排序 
+		 {
+		 	for(int m=i;m<i+con;m++)
+			{
+				for(int n=i;n<=i+con-1;n++)
+				{
+					if(information[n].sum<information[n+1].sum)
+			 		{
+						struct Student tmp=information[n];
+						information[n]=information[n+1];
+						information[n+1]=tmp;
+					 }
+				 }
+			 }
+		 }	 
+		 i=i+con;
+	  } 
+}
+
+
+//按格式输出 
+void output(struct Student information[4],int start,int end)
+{
+	//排完序后输出
+	for(int i=start;i<=end;i++)
+	{
+		printf("%d %d ",information[i].ID,information[i].classes);
+		for(int j=0;information[i].name[j]!='\0';j++)
+		{
+			printf("%c",information[i].name[j]);
+		}
+		printf(" %.1f %.1f %.1f\n",information[i].math_grade,\
+		information[i].physics_grade,information[i].English_grade);
+	}
+}
+
+int pow10(int M)
+{
+	int num=1;
+	for(int i=1;i<=M;i++)
+	{
+		num*=10;
+	}
+	
+	return num;
+}
+//在结构体中的从start同学到end同学里面查找要删掉的同学 
+int original_location(char delete_student[8],struct Student information[4],int start,int end)
+{
+	int mark=MARK;//标记被删除信息学生的初始位置 ,初始化为MARK方便区分 
+	if(delete_student[0]<='9'&&delete_student[0]>='0')
+	{
+		int num=0;
+		for(int i=0;i<strlen(delete_student);i++)
+		{
+			num+=(delete_student[i]-'0')*pow10(strlen(delete_student)-i-1);
+		}
+		for(int i=0;i<=2;i++)
+		{
+			if(num==information[i].ID)
+			{
+				mark=i;
+				break;
+			}
+		}
+	}
+	else//输入了字符串 
+	{
+		for(int i=0;i<=2;i++)
+		{
+			if(strcmp(delete_student,information[i].name)==0)
+			{
+				mark=i;
+				break;
+			}
+		}
+	 } 
+	 
+	 return mark;
+}
+int main()
+{
+	struct Student information[4];
+	//已有三个同学的信息
+	information[0].ID=10001;strcpy(information[0].name, "Zhang");
+	information[0].classes=11;information[0].math_grade=99.5;
+	information[0].physics_grade=88.5;information[0].English_grade=89.5;
+	information[0].sum=99.5+88.5+89.5;
+	
+	information[1].ID=10002;strcpy(information[1].name, "Yang");
+	information[1].classes=12;information[1].math_grade=77.9;
+	information[1].physics_grade=56.5;information[1].English_grade=87.5;
+	information[1].sum=77.9+56.5+87.5;
+	
+	information[2].ID=10003;strcpy(information[2].name, "Liang");
+	information[2].classes=11;information[2].math_grade=92.5;
+	information[2].physics_grade=99.0;information[2].English_grade=60.5;
+	information[2].sum=92.5+99.0+60.5;
+	
+	//输入被删除同学的信息 
+	char delete_student[8];
+	scanf("%s", delete_student);
+	
+	//判断同学是否在系统里面 
+	 if(original_location(delete_student,information,0,2)==MARK)
+	 {
+	 //说明同学不在系统里面
+	 	Sort(information,0,2);	
+		output(information,0,2);
+	} 
+	else
+	{
+	  	struct Student left[4];
+	  	int j=0;
+	  	for(int i=0;i<=2;i++)
+	  	{
+	  		if(i!=original_location(delete_student,information,0,2))
+	  		{
+	  		left[j]=information[i];
+			  j++;	
+			  }
+	  		
+		}
+		
+		Sort(left,0,1);	
+		output(left,0,1);
+	
+	
+		printf("Are you sure(yes/no)?\n");
+		char ch[1];
+		scanf("%s",ch);
+		if(ch[0]=='n')
+		{
+			Sort(information,0,2);
+			output(information,0,2);
+		}
+	}
+}
+ 
+
+