ADD file via upload

4.c

@@ -0,0 +1,89 @@
+#include <stdio.h>
+
+struct Data
+{
+	int ID;
+	int Class;
+	float score1;
+	float score2;
+	float score3;
+} stu[1001];
+int stl = 0;
+struct Data* stuflag;
+
+float total(struct Data* a) {
+	return a->score1 + a->score2 + a->score3;
+}
+
+void swap(struct Data* a, struct Data* b) {
+	struct Data t = *a;
+	*a = *b;
+	*b = t;
+
+	if (a == stuflag) stuflag = b;
+else 
+	if (b == stuflag) stuflag = a;
+}
+
+void Sort() {
+	int i, j;
+	for(i = 0; i < stl-1; i++) {
+		for (j = 0; j < stl-i-1; j++) {
+			if (stu[j].Class < stu[j+1].Class) continue;
+			if (stu[j].Class > stu[j+1].Class || 
+			total(&stu[j]) < total(&stu[j+1])) swap(&stu[j], &stu[j+1]);
+		}
+	}
+}
+
+void input1() {
+	scanf("%d", &stu[stl].ID);
+	scanf("%f", &stu[stl].score1);
+	scanf("%f", &stu[stl].score2);
+	scanf("%f", &stu[stl].score3);
+	stl++;
+}
+
+
+void Input() {
+	printf("Please input info of three students:\n");
+	input1();input1();input1();
+	if (total(&stu[stl-3]) < total(&stu[stl-2])) swap(&stu[stl-3], &stu[stl-2]);
+	if (total(&stu[stl-2]) < total(&stu[stl-1])) swap(&stu[stl-2], &stu[stl-1]);
+	if (total(&stu[stl-3]) < total(&stu[stl-2])) swap(&stu[stl-3], &stu[stl-2]);
+	printf("%d,%.1f,%.1f\n", stu[stl-3].ID, total(&stu[stl-3]), total(&stu[stl-3])/3.0f);
+	printf("%d,%.1f,%.1f\n", stu[stl-2].ID, total(&stu[stl-2]), total(&stu[stl-2])/3.0f);
+	printf("%d,%.1f,%.1f\n", stu[stl-1].ID, total(&stu[stl-1]), total(&stu[stl-1])/3.0f);
+}
+
+void print1(struct Data* a) {
+	printf("%d %d %2.1f %2.1f %2.1f", a->ID, a->Class,
+					a->score1, a->score2, a->score3);
+	if (a == stuflag) printf(" inserted");
+	printf("\n");
+}
+
+void Insert() {
+	stu[0] = (struct Data){10001, 11, 99.5, 88.5, 89.5};
+	stu[1] = (struct Data){10002, 12, 77.9, 56.5, 87.5};
+	stu[2] = (struct Data){10003, 11, 92.5, 89.0, 60.5};
+	stl = 3;
+	
+	scanf("%d", &stu[stl].ID);
+	scanf("%d", &stu[stl].Class);
+	scanf("%f", &stu[stl].score1);
+	scanf("%f", &stu[stl].score2);
+	scanf("%f", &stu[stl].score3);
+	stl++;
+	
+	stuflag = stu + 3;
+	Sort();
+	print1(stu + 0);
+	print1(stu + 1);
+	print1(stu + 2);
+	print1(stu + 3);
+}
+
+int main() {
+	Insert();
+}