diff --git a/README.md b/README.md
index 868e0ef..f3365d1 100644
--- a/README.md
+++ b/README.md
@@ -1,65 +1,97 @@
-# Student_registration_management_system
 #include <stdio.h>
-#include <stdlib.h>
 #include <string.h>
 
+// 定义学生结构体
 struct Student {
-    char id[20];
-    char clas[20];
+    char id[10];
+    int class;
     char name[20];
-    double score1;
-    double score2;
-    double score3;
-    double score;
+    float score1;
+    float score2;
+    float score3;
 };
 
-// Function prototypes
-void inputStudent(struct Student *stu);
-void deleteStudent(struct Student *stu, int *numStudents);
-void selectStudent(struct Student *stu, int numStudents);
-
-int main() {
-    struct Student students[100];  // Adjust the size as needed
-    int numStudents = 0;
-    int option;
+// 修改学生信息函数
+void modifyStudent(struct Student students[], int numStudents, char key[], int newClass, char newName[], float newScore1, float newScore2, float newScore3) {
+    // 查找待修改学生的位置
+    for (int i = 0; i < numStudents; i++) {
+        if (strcmp(students[i].id, key) == 0) {
+            // 找到学生，修改信息
+            students[i].class = newClass;
+            strcpy(students[i].name, newName);
+            students[i].score1 = newScore1;
+            students[i].score2 = newScore2;
+            students[i].score3 = newScore3;
+            break;
+        }
+    }
+}
 
-    do {
-        // Display menu
-        printf("1. Input\n2. Delete\n3. Select\n4. Order\n5. Output\n6. Quit\n");
-        printf("Please input your option: ");
-        scanf("%d", &option);
+// 输出学生信息函数
+void printStudents(struct Student students[], int numStudents) {
+    for (int i = 0; i < numStudents; i++) {
+        if (i == 0 || students[i].class != students[i - 1].class) {
+            // 输出班级信息
+            printf("%d %s %s %.1f %.1f %.1f", students[i].class, students[i].id, students[i].name, students[i].score1, students[i].score2, students[i].score3);
+        } else {
+            // 缩进输出
+            printf("   %s %s %.1f %.1f %.1f", students[i].id, students[i].name, students[i].score1, students[i].score2, students[i].score3);
+        }
 
-        switch (option) {
-            case 1:
-                inputStudent(&students[numStudents]);
-                numStudents++;
-                break;
-            case 2:
-                deleteStudent(students, &numStudents);
-                break;
-            case 3:
-                selectStudent(students, numStudents);
-                break;
-            // Add cases for other options (order, output) if needed
-            case 6:
-                printf("Exiting the program.\n");
-                break;
-            default:
-                printf("Invalid option. Please try again.\n");
+        if (i == numStudents - 1) {
+            // 输出 modified
+            printf(" modified");
         }
-    } while (option != 6);
 
-    return 0;
+        printf("\n");
+    }
 }
 
-void inputStudent(struct Student *stu) {
-    
-}
+int main() {
+    // 初始化已有学生信息
+    struct Student students[3] = {
+        {"10001", 11, "Zhang", 99.5, 88.5, 89.5},
+        {"10002", 12, "Yang", 77.9, 56.5, 87.5},
+        {"10003", 11, "Liang", 92.5, 99.0, 60.5}
+    };
 
-void deleteStudent(struct Student *stu, int *numStudents) {
-   
-}
+    int numStudents = 3; // 已有学生数量
 
-void selectStudent(struct Student *stu, int numStudents) {
-    
+    // 输入待修改学生的信息
+    char key[10];
+    int newClass;
+    char newName[20];
+    float newScore1, newScore2, newScore3;
+
+    printf("请输入待修改学生的学号：");
+    scanf("%s", key);
+
+    // 查找学生并输入新的信息
+    for (int i = 0; i < numStudents; i++) {
+        if (strcmp(students[i].id, key) == 0) {
+            printf("请输入新的班级：");
+            scanf("%d", &newClass);
+            printf("请输入新的姓名：");
+            scanf("%s", newName);
+            printf("请输入新的成绩1：");
+            scanf("%f", &newScore1);
+            printf("请输入新的成绩2：");
+            scanf("%f", &newScore2);
+            printf("请输入新的成绩3：");
+            scanf("%f", &newScore3);
+
+            // 调用修改函数
+            modifyStudent(students, numStudents, key, newClass, newName, newScore1, newScore2, newScore3);
+
+            // 输出更新后的学生信息
+            printStudents(students, numStudents);
+
+            return 0;
+        }
+    }
+
+    // 如果未找到学生，直接输出原有学生信息
+    printStudents(students, numStudents);
+
+    return 0;
 }