diff --git a/s3.c b/s3.c
new file mode 100644
index 0000000..65dfd0c
--- /dev/null
+++ b/s3.c
@@ -0,0 +1,90 @@
+#include <stdio.h>
+//定义结构组 
+typedef struct {
+    int student_id;
+    float math_grade;
+    float physics_grade;
+    float english_grade;
+    float total_grade;
+    float average_grade;
+} Student;
+//录入学生信息 
+void inputInfo() {
+    printf("Please input info of the three students:\n");
+
+    Student students[3];
+
+    for (int i = 0; i < 3; i++) {
+        //其实有printf注明以下正在录入的信息是什么更好  
+        //printf("ID"); 
+        scanf("%d", &students[i].student_id);
+        //printf("math grade");
+        scanf("%f", &students[i].math_grade);
+        //printf("physics grade");
+        scanf("%f", &students[i].physics_grade);
+        //printf("english grade");
+        scanf("%f", &students[i].english_grade);
+
+        students[i].total_grade = students[i].math_grade + students[i].physics_grade + students[i].english_grade;
+        students[i].average_grade = students[i].total_grade / 3.0;
+
+       
+    }
+
+    // 排序 
+    for (int i = 0; i < 3; i++) {
+        for (int j = 0; j < 2 - i; j++) {
+            if (students[j].total_grade > students[j + 1].total_grade) {
+               
+                Student temp = students[j];
+                students[j] = students[j + 1];
+                students[j + 1] = temp;
+            }
+        }
+    }
+
+    //输出学号,总成绩，平均 
+    for (int i = 0; i < 3; i++) {
+        printf("%d,%.1f,%.1f\n", students[i].student_id,students[i].total_grade,students[i].average_grade);
+    }
+}
+
+void outputInfo() {
+    printf("You are trying to Output info.\n");
+}
+
+void makeOrdered() {
+    printf("You are trying to Make things ordered.\n");
+}
+//菜单 
+int main() {
+    char choice;
+
+    printf("Main Menu:\n");
+    printf("%30s 1.Input\n", "");
+    printf("%30s 2.Output\n", "");
+    printf("%30s 3.Order\n", "");
+    printf("%30s 4.Quit\n", "");
+    printf("Please enter your choice: ");
+    scanf(" %c", &choice);
+//选择 
+    switch (choice) {
+        case 'i':
+            inputInfo();
+            break;
+        case 'o':
+            outputInfo();
+            break;
+        case 'm':
+            makeOrdered();
+            break;
+        case 'q':
+            printf("You are about to Quit.\n");
+            break;
+        default:
+            printf("Wrong input.\n");
+            break;
+    }
+
+    return 0;
+}