Add step4

step4

@@ -0,0 +1,143 @@
+#include<stdio.h>
+#include<string.h>
+#define size 4
+int main()
+{
+	//前面需要输入学生信息的函数，此处我就瞎定义几个为了方便测试
+	//int sum();
+	void sequence();
+	int count();
+	struct Student
+	{
+		int class;//[size];
+		int number, score;
+		int ans;
+		int score1, score2, all_score;//三门成绩分别为score，score1，score2，all_score为了求和
+	}Student[size + 1], temp;
+	Student[0].class = 11;
+	Student[1].class = 11;
+	Student[2].class = 12;
+	Student[0].number = 10001;
+	Student[1].number = 10002;
+	Student[2].number = 10004;
+	Student[0].score = 90; Student[0].score1 = 90; Student[0].score2 = 90;
+	Student[1].score = 83; Student[1].score1 = 84; Student[1].score2 = 85;
+	Student[2].score = 83; Student[2].score1 = 70; Student[2].score2 = 90;
+	int size1;
+	size1 = count(Student[size-1].number);
+
+	//输入的部分替换为输入函数
+	/*scanf("%d%d%d%d", &class[0], &class[1], &class[2], &class[3]);
+	scanf("%d%d%d%d", &number[0], &number[1], &number[2], &number[3]);
+	scanf("%d%d", &all_score[0], &all_score[1]);*/
+	printf("please enter the information:");
+	//上面是我写的输入，下面是插入函数的部分
+	scanf_s("%d", &Student[size - 1].class);
+	scanf_s("%d", &Student[size - 1].number);
+	int c = Student[size - 1].number;//记住学生学号
+	//scanf_s("%d", &Student[size-1].class);
+	scanf_s("%d%d%d", &Student[size - 1].score, &Student[size - 1].score1, &Student[size - 1].score2); //&Student[size - 1].all_score);//输入学生信息
+	/*for (int count1 = 0; count1 < size; count1++)
+	{
+		printf("%d %d %d %d %d", Student[count1].class, Student[count1].number, Student[count1].score, Student[count1].score1, Student[count1].score2);
+		if (c == Student[count1].number)//显示插入的学生
+		{
+			printf("  inserted");
+		}
+		printf("\n");
+	}*/
+	//根据班级排序
+	int count2 = 0, count3 = 0;
+	for (count2 = 0; count2 < size; count2++)
+	{
+		for (count3 = count2 + 1; count3 < size; count3++)
+		{
+			if (Student[count2].class > Student[count3].class )
+			{
+				temp = Student[count2];
+				Student[count2] = Student[count3];
+				Student[count3] = temp;
+			}
+		}
+	}
+
+	for (int count4 = 0; count4 < size; count4++)
+	{
+		Student[count4].all_score = Student[count4].score+Student[count4].score1 + Student[count4].score2;
+	}
+	//同班根据成绩排序
+	count2=0, count3=0;
+	for (count2 = 0; count2 < size; count2++)
+	{
+		for (count3 = count2 + 1; count3 < size; count3++)
+		{
+			if (Student[count2].class == Student[count3].class && Student[count2].all_score < Student[count3].all_score)
+			{
+				temp = Student[count2];
+				Student[count2] = Student[count3];
+				Student[count3] = temp;
+			}
+		}
+	}
+
+	for (int count1 = 0; count1 < size; count1++)
+	{
+		printf("%d  %d  %d  %d  %d", Student[count1].class, Student[count1].number, Student[count1].score, Student[count1].score1, Student[count1].score2);
+		if (c == Student[count1].number)//显示插入的学生
+		{
+			printf("   inserted");
+		}
+		printf("\n");
+	}
+	return 0;
+}
+//排序函数
+void sequence(int arr[size])
+{
+	int temp;
+	for (int count1 = 1; count1 <= size; count1++)
+	{
+		for (int count2 = 1; count2 <= size - count1; count2++)
+		{
+			if (arr[count2 - 1] > arr[count2])
+			{
+				temp = arr[count2];
+				arr[count2] = arr[count2 + 1];
+				arr[count2 + 1] = temp;
+			}
+		}
+	}
+}
+
+//求和函数
+int sum(int x, int y, int z)
+{
+	int ans;
+	ans = x + y + z;
+	return ans;
+}
+
+
+//为了定义数组的长度，所以写了一个检测的函数,即把size改为size1+1
+//size1是数组真实的长度
+//size是我为了方便定义的全局变量
+int count(int arr[])
+{
+	int len;
+	len = sizeof(arr) / sizeof(arr[0]);
+	return len;
+}
+
+/*
+//交换函数
+void change(int number1,int number2,int real_change1,int real_change2)
+{
+	int temp;
+	if (number1 > number2)
+	{
+		temp = real_change1;
+		real_change1 = real_change2;
+		real_change2 = temp;
+	}
+}
+*/