diff --git a/作业2.6.c b/作业2.6.c
new file mode 100644
index 0000000..573a560
--- /dev/null
+++ b/作业2.6.c
@@ -0,0 +1,84 @@
+#include <stdio.h>
+#include <stdlib.h> // °üº¬ÁË qsort º¯ÊýËùÐèµÄÍ·Îļþ
+#include <string.h> // °üº¬ÁË×Ö·û´®´¦Àíº¯ÊýËùÐèµÄÍ·Îļþ
+
+// ѧÉúÐÅÏ¢µÄ½á¹¹Ìå
+struct Student {
+    int student_id;
+    int class_id;
+    char name[50];
+    float score1;
+    float score2;
+    float score3;
+};
+
+// ±È½Ïº¯Êý£¬ÓÃÓÚÅÅÐò
+int compareStudents(const void *a, const void *b) {
+    struct Student *student1 = (struct Student *)a;
+    struct Student *student2 = (struct Student *)b;
+
+    if (student1->class_id != student2->class_id) {
+        return student1->class_id - student2->class_id;
+    } else {
+        float total_score1 = student1->score1 + student1->score2 + student1->score3;
+        float total_score2 = student2->score1 + student2->score2 + student2->score3;
+        return total_score2 - total_score1;
+    }
+}
+
+int main() {
+    struct Student students[100];
+    int num_students = 3;  // ³õʼÓÐ3¸öѧÉúÐÅÏ¢
+
+    // ³õʼ»¯ÒÑÓÐѧÉúÐÅÏ¢
+    students[0] = (struct Student){10001, 11, "Zhang", 99.5, 88.5, 89.5};
+    students[1] = (struct Student){10002, 12, "Yang", 77.9, 56.5, 87.5};
+    students[2] = (struct Student){10003, 11, "Liang", 92.5, 99.0, 60.5};
+
+    // ¶ÔÒÑÓÐѧÉúÐÅÏ¢½øÐÐÅÅÐò
+    qsort(students, num_students, sizeof(struct Student), compareStudents);
+
+    // ÊäÈë´ýÐÞ¸ÄѧÉúµÄÐÅÏ¢
+    struct Student modified_student;
+    printf("ÊäÈë´ýÐÞ¸ÄѧÉúµÄÐÅÏ¢£¨Ñ§ºÅ °à¼¶ ÐÕÃû ³É¼¨1 ³É¼¨2 ³É¼¨3£©£º");
+    scanf("%d %d %s %f %f %f", &modified_student.student_id, &modified_student.class_id, modified_student.name, &modified_student.score1, &modified_student.score2, &modified_student.score3);
+
+    // ¼ì²éѧºÅÊÇ·ñ´æÔÚ£¬Èç¹û²»´æÔÚ£¬Êä³öÔ­ÓÐÈý¸öѧÉúÐÅÏ¢²¢Í˳ö³ÌÐò
+    int found = 0;
+    for (int i = 0; i < num_students; i++) {
+        if (modified_student.student_id == students[i].student_id) {
+            found = 1;
+            students[i] = modified_student;
+            break;
+        }
+    }
+
+    if (!found) {
+        printf("¸ÃѧÉúÐÅÏ¢²»´æÔÚ£¬Êä³öÔ­ÓÐÈý¸öѧÉúÐÅÏ¢²¢Í˳ö³ÌÐò£º\n");
+        for (int i = 0; i < num_students; i++) {
+            printf("%d %d %s %.1f %.1f %.1f\n", students[i].student_id, students[i].class_id, students[i].name, students[i].score1, students[i].score2, students[i].score3);
+        }
+        return 0;
+    }
+
+    // ¶ÔÐÂÊý¾Ý½øÐÐÅÅÐò
+    qsort(students, num_students, sizeof(struct Student), compareStudents);
+
+    // Êä³öѧÉúÐÅÏ¢
+    for (int i = 0; i < num_students; i++) {
+        if (i == 0 || students[i].class_id != students[i - 1].class_id) {
+            printf("%d %d %s %.1f %.1f %.1f", students[i].student_id, students[i].class_id, students[i].name, students[i].score1, students[i].score2, students[i].score3);
+        } else {
+            printf("   %d %s %.1f %.1f %.1f", students[i].student_id, students[i].name, students[i].score1, students[i].score2, students[i].score3);
+        }
+
+        if (i == num_students - 1) {
+            printf(" modified\n");
+        } else {
+            printf("\n");
+        }
+    }
+
+    return 0;
+}
+