diff --git a/step4.c b/step4.c
index a450776..36ddd8b 100644
--- a/step4.c
+++ b/step4.c
@@ -1,93 +1,93 @@
-#include <stdio.h>
-#include<stdlib.h>
-typedef struct {
-    int id;
-    int classNum;
-    float score1;
-    float score2;
-    float score3;
-} Student;
-
-// 函数声明
-int compareStudents(const void *a, const void *b);
-void insertStudent(Student students[], int *size, Student newStudent);
-void printStudents(Student students[], int size);
-
-int main() {
-    Student students[4] = {
-        {10001, 11, 99.5, 88.5, 89.5},
-        {10002, 12, 77.9, 56.5, 87.5},
-        {10003, 11, 92.5, 99.0, 60.5}
-    };
-    int size = 3; // 当前学生数量
-    Student newStudent;
-
-    // 输入新学生的信息
-    printf("");
-    scanf("%d",&newStudent.id);
-     printf("");
-     scanf("%d",&newStudent.classNum);
-      printf("");
-      scanf("%f",&newStudent.score1);
-       printf("");
-       scanf("%f",&newStudent.score2);
-       printf("");
-       scanf("%f",&newStudent.score3);
-    // 检查学号是否已存在
-    int i;
-    for (i = 0; i < size; i++) {
-        if (students[i].id == newStudent.id) {
-            printf("学号 %d 已存在。\n", newStudent.id);
-            return 0;
-        }
-    }
-
-    // 插入新学生
-    insertStudent(students, &size, newStudent);
-
-    // 打印所有学生信息
-    printStudents(students, size);
-
-    return 0;
-}
-
-// 比较函数，用于qsort
-int compareStudents(const void *a, const void *b) {
-    Student *studentA = (Student *)a;
-    Student *studentB = (Student *)b;
-    if (studentA->classNum != studentB->classNum) {
-        return studentA->classNum - studentB->classNum;
-    } else {
-        float totalA = studentA->score1 + studentA->score2 + studentA->score3;
-        float totalB = studentB->score1 + studentB->score2 + studentB->score3;
-        return (totalB > totalA) - (totalA > totalB);
-    }
-}
-
-// 插入新学生
-void insertStudent(Student students[], int *size, Student newStudent) {
-    Student temp[*size + 1];
-    int i;
-    for (i = 0; i < *size; i++) {
-        temp[i] = students[i];
-    }
-    temp[*size] = newStudent;
-    qsort(temp, *size + 1, sizeof(Student), compareStudents);
-    for (i = 0; i < *size + 1; i++) {
-        students[i] = temp[i];
-    }
-    (*size)++;
-}
-
-// 打印学生信息
-void printStudents(Student students[], int size) {
-	int i;
-    for (i = 0; i < size; i++) {
-        printf("%d %d %.1f %.1f %.1f", students[i].id, students[i].classNum, students[i].score1, students[i].score2, students[i].score3);
-        if (i == size-2) {
-            printf(" inserted\n");
-        } else {
-            printf("\n");
-        }
-    }
-}
+#include <stdio.h>
+#include<stdlib.h>
+typedef struct {
+    int id;
+    int classNum;
+    float score1;
+    float score2;
+    float score3;
+} Student;
+
+// 函数声明
+int compareStudents(const void *a, const void *b);
+void insertStudent(Student students[], int *size, Student newStudent);
+void printStudents(Student students[], int size);
+
+int main() {
+    Student students[4] = {
+        {10001, 11, 99.5, 88.5, 89.5},
+        {10002, 12, 77.9, 56.5, 87.5},
+        {10003, 11, 92.5, 99.0, 60.5}
+    };
+    int size = 3; // 当前学生数量
+    Student newStudent;
+
+    // 输入新学生的信息
+    printf("");
+    scanf("%d",&newStudent.id);
+     printf("");
+     scanf("%d",&newStudent.classNum);
+      printf("");
+      scanf("%f",&newStudent.score1);
+       printf("");
+       scanf("%f",&newStudent.score2);
+       printf("");
+       scanf("%f",&newStudent.score3);
+    // 检查学号是否已存在
+    int i;
+    for (i = 0; i < size; i++) {
+        if (students[i].id == newStudent.id) {
+            printf("学号 %d 已存在。\n", newStudent.id);
+            return 0;
+        }
+    }
+
+    // 插入新学生
+    insertStudent(students, &size, newStudent);
+
+    // 打印所有学生信息
+    printStudents(students, size);
+
+    return 0;
+}
+
+// 比较函数，用于qsort
+int compareStudents(const void *a, const void *b) {
+    Student *studentA = (Student *)a;
+    Student *studentB = (Student *)b;
+    if (studentA->classNum != studentB->classNum) {
+        return studentA->classNum - studentB->classNum;
+    } else {
+        float totalA = studentA->score1 + studentA->score2 + studentA->score3;
+        float totalB = studentB->score1 + studentB->score2 + studentB->score3;
+        return (totalB > totalA) - (totalA > totalB);
+    }
+}
+
+// 插入新学生
+void insertStudent(Student students[], int *size, Student newStudent) {
+    Student temp[*size + 1];
+    int i;
+    for (i = 0; i < *size; i++) {
+        temp[i] = students[i];
+    }
+    temp[*size] = newStudent;
+    qsort(temp, *size + 1, sizeof(Student), compareStudents);
+   for (i = 0; i < *size + 1; i++) {
+        students[i] = temp[i];
+    }
+    (*size)++;
+}
+
+// 打印学生信息
+void printStudents(Student students[], int size) {
+	int i;
+    for (i = 0; i < size; i++) {
+        printf("%d %d %.1f %.1f %.1f", students[i].id, students[i].classNum, students[i].score1, students[i].score2, students[i].score3);
+        if (i == size-2) {
+            printf(" inserted\n");
+        } else {
+            printf("\n");
+        }
+    }
+}