diff --git a/7.c b/7.c
new file mode 100644
index 0000000..1870ecb
--- /dev/null
+++ b/7.c
@@ -0,0 +1,109 @@
+#include <stdio.h>
+#include <string.h>
+
+#define MAX_STUDENTS 100
+
+struct student {
+    int id;
+    int class;
+    char name[20];
+    float score1;
+    float score2;
+    float score3;
+};
+
+void input(struct student students[], int* num_students);
+void search(struct student students[], int num_students, char* query);
+void sort(struct student students[], int num_students);
+void output(struct student students[], int num_students);
+
+int main() {
+    struct student students[MAX_STUDENTS] = {
+           {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},
+           {10004, 11, "Cai", 89.6, 56.9, 90.5},
+           {10005, 14, "Fu", 55.6, 67.9, 98.9},
+           {10006, 12, "Mao", 22.1, 45.9, 99.2},
+           {10007, 13, "Zhan", 35.6, 67.9, 88.0}
+    };
+    int num_students = 7;
+
+    input(students, &num_students);
+
+    char query[20];
+    printf("请输入查询要求：\n");
+    scanf("%s", query);
+    search(students, num_students, query);
+    sort(students, num_students);
+    output(students, num_students);
+
+    return 0;
+}
+
+void input(struct student students[], int* num_students) {
+    FILE* fp = fopen("students.txt", "r");
+    if (fp == NULL) {
+        return;
+    }
+    while (*num_students < MAX_STUDENTS && fscanf(fp, "%d %d %s %f %f %f", &students[*num_students].id, &students[*num_students].class, students[*num_students].name, &students[*num_students].score1, &students[*num_students].score2, &students[*num_students].score3) == 6) {
+        (*num_students)++;
+    }
+    fclose(fp);
+}
+
+void search(struct student students[], int num_students, char* query) {
+    int i;
+    printf("查询结果如下：\n");
+    for (i = 0; i < num_students; i++) {
+        struct student s = students[i];
+        if (query[0] == '1') {
+            int class_start, class_end;
+            sscanf(query + 2, "%d-%d", &class_start, &class_end);
+            if (s.class >= class_start && s.class <= class_end) {
+                printf("%d %d %s %.1f %.1f %.1f\n", s.id, s.class, s.name, s.score1, s.score2, s.score3);
+            }
+        }
+        else if (query[0] == '2') {
+            int id_start, id_end;
+            sscanf(query + 2, "%d-%d", &id_start, &id_end);
+            if (s.id >= id_start && s.id <= id_end) {
+                printf("%d %d %s %.1f %.1f %.1f\n", s.id, s.class, s.name, s.score1, s.score2, s.score3);
+            }
+        }
+        else if (query[0] == '3') {
+            if (strstr(s.name, query + 1) == s.name) {
+                printf("%d %d %s %.1f %.1f %.1f\n", s.id, s.class, s.name, s.score1, s.score2, s.score3);
+            }
+        }
+        else if (query[0] == '4') {
+            float score;
+            sscanf(query + 2, "%f", &score);
+            if (s.score1 + s.score2 + s.score3 >= score) {
+                printf("%d %d %s %.1f %.1f %.1f\n", s.id, s.class, s.name, s.score1, s.score2, s.score3);
+            }
+        }
+    }
+}
+void sort(struct student students[], int num_students) {
+    int i, j;
+    struct student temp;
+    for (i = 0; i < num_students - 1; i++) {
+        for (j = 0; j < num_students - i - 1; j++) {
+            if (students[j].id > students[j + 1].id) {
+                temp = students[j];
+                students[j] = students[j + 1];
+                students[j + 1] = temp;
+            }
+        }
+    }
+}
+
+void output(struct student students[], int num_students) {
+    int i;
+    printf("学号\t班级\t姓名\t\t科目1\t科目2\t科目3\n");
+    for (i = 0; i < num_students; i++) {
+        struct student s = students[i];
+        printf("%d\t%d\t%-12s\t%.1f\t%.1f\t%.1f\n", s.id, s.class, s.name, s.score1, s.score2, s.score3);
+    }
+}
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