diff --git a/Array_program.c b/Array_program.c
new file mode 100644
index 0000000..75b3ea3
--- /dev/null
+++ b/Array_program.c
@@ -0,0 +1,267 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+// 定义学生结构体
+typedef struct Student {
+    char id[20];
+    char clas[20];
+    char name[20];
+    double score1, score2, score3, totalScore;
+} Student;
+
+#define MAX_STUDENTS 100
+Student students[MAX_STUDENTS];
+int count = 0;
+
+void menu();
+void input();
+void delete();
+void select();
+void sort();
+void output();
+
+int main() {
+    char option;
+
+    while (1) {
+        menu();
+        printf("please input your option: ");
+        scanf(" %c", &option);
+        
+        switch (option) {
+            case '1':
+                input();
+                break;
+            case '2':
+                delete();
+                break;
+            case '3':
+                select();
+                break;
+            case '4':
+                sort();
+                break;
+            case '5':
+                output();
+                break;
+            case '6':
+                printf("Exiting.\n");
+                return 0;
+            default:
+                printf("Invalid option.\n");
+        }
+    }
+    return 0;
+}
+
+void menu() {
+    printf("\n");
+    printf("1.input\n");
+    printf("2.delete\n");
+    printf("3.select\n");
+    printf("4.order\n");
+    printf("5.output\n");
+    printf("6.quit\n");
+}
+
+void input() {
+    while (1) {
+        if (count >= MAX_STUDENTS) {
+            printf("Maximum number of students reached.\n");
+            return;
+        }
+        Student buffer;
+        printf("Id: ");
+        scanf("%s", buffer.id);
+        printf("Class: ");
+        scanf("%s", buffer.clas);
+        printf("Name: ");
+        scanf("%s", buffer.name);
+        printf("Score1: ");
+        scanf("%lf", &buffer.score1);
+        printf("Score2: ");
+        scanf("%lf", &buffer.score2);
+        printf("Score3: ");
+        scanf("%lf", &buffer.score3);
+
+        buffer.totalScore = buffer.score1 + buffer.score2 + buffer.score3;
+        students[count++] = buffer;
+
+        char cont[4];
+        printf("continue? (yes/no): ");
+        scanf("%s", cont);
+        if (cont[0] == 'n') break;
+    }
+}
+
+void delete() {
+    if (count == 0) {
+        printf("No students.\n");
+        return;
+    }
+
+    char key[20];
+    printf("Enter student ID or name to delete: ");
+    scanf("%s", key);
+
+    int i, boo1 = 0;
+    for (i = 0; i < count; i++) {
+        if (strcmp(students[i].id, key) == 0 || strcmp(students[i].name, key) == 0) {
+            boo1 = 1;
+            break;
+        }
+    }
+    int j;
+    if (boo1) {
+        for (j = i; j < count - 1; j++) {
+            students[j] = students[j + 1];
+        }
+        count--;
+        printf("Student deleted successfully.\n");
+        output();
+    } else {
+        printf("Student not found.\n");
+        output();
+    }
+}
+
+// void select() {
+//     char key[20];
+//     printf("Enter student ID, name, or class to search: ");
+//     scanf("%s", key);
+
+//     int boo1 = 0;
+//     int i;
+//     for (i = 0; i < count; i++) {
+//         if (strcmp(students[i].id, key) == 0 || strcmp(students[i].name, key) == 0 || strcmp(students[i].clas, key) == 0) {
+//             printf("%s %s %s %.1f %.1f %.1f %.1f\n", students[i].id, students[i].clas, students[i].name,
+//                    students[i].score1, students[i].score2, students[i].score3, students[i].totalScore);
+//             boo1 = 1;
+//         }
+//     }
+
+//     if (!boo1) {
+//         printf("No eligible student found.\n");
+//     }
+// }
+
+void select() {
+    char input[50];
+    printf("Enter your query (e.g., 1 classNum-classNum, 2 idNum-idNum, 3 namePrefix*, 4 minScore, 5 classNum.idNum-idNum): ");
+    scanf(" %[^\n]", input); 
+
+    int type = input[0] - '0'; 
+    char condition[50];
+    strcpy(condition, input + 2); 
+
+    int boo1 = 0; 
+
+    switch (type) {
+        case 1: { 
+            int startClass, endClass;
+            sscanf(condition, "%d-%d", &startClass, &endClass);
+            int i;
+            for (i = 0; i < count; i++) {
+                int class = atoi(students[i].clas);
+                if (class >= startClass && class <= endClass) {
+                    printf("%s %s %s %.1f %.1f %.1f %.1f\n", students[i].id, students[i].clas, students[i].name,
+                           students[i].score1, students[i].score2, students[i].score3, students[i].totalScore);
+                    boo1 = 1;
+                }
+            }
+            break;
+        }
+        case 2: { 
+            int startId, endId;
+            sscanf(condition, "%d-%d", &startId, &endId);
+            int i;
+            for (i = 0; i < count; i++) {
+                int id = atoi(students[i].id);
+                if (id >= startId && id <= endId) {
+                    printf("%s %s %s %.1f %.1f %.1f %.1f\n", students[i].id, students[i].clas, students[i].name,
+                           students[i].score1, students[i].score2, students[i].score3, students[i].totalScore);
+                    boo1 = 1;
+                }
+            }
+            break;
+        }
+        case 3: { 
+            char prefix[20];
+            sscanf(condition, "%s", prefix);
+            int prefixLen = strlen(prefix) - 1; 
+            int i;
+            for (i = 0; i < count; i++) {
+                if (strncmp(students[i].name, prefix, prefixLen) == 0) {
+                    printf("%s %s %s %.1f %.1f %.1f %.1f\n", students[i].id, students[i].clas, students[i].name,
+                           students[i].score1, students[i].score2, students[i].score3, students[i].totalScore);
+                    boo1 = 1;
+                }
+            }
+            break;
+        }
+        case 4: { 
+            double minScore;
+            sscanf(condition, "%lf", &minScore);
+            int i;
+            for (i = 0; i < count; i++) {
+                if (students[i].totalScore >= minScore) {
+                    printf("%s %s %s %.1f %.1f %.1f %.1f\n", students[i].id, students[i].clas, students[i].name,
+                           students[i].score1, students[i].score2, students[i].score3, students[i].totalScore);
+                    boo1 = 1;
+                }
+            }
+            break;
+        }
+        case 5: { 
+            int class, startId, endId;
+            sscanf(condition, "%d.%d-%d", &class, &startId, &endId);
+            int i;
+            for (i = 0; i < count; i++) {
+                int studentClass = atoi(students[i].clas);
+                int studentId = atoi(students[i].id);
+
+                if (studentClass == class && studentId >= startId && studentId <= endId) {
+                    printf("%s %s %s %.1f %.1f %.1f %.1f\n", students[i].id, students[i].clas, students[i].name,
+                           students[i].score1, students[i].score2, students[i].score3, students[i].totalScore);
+                    boo1 = 1;
+                }
+            }
+            break;
+        }
+        default:
+            printf("Invalid query type.\n");
+            return;
+    }
+    if (!boo1) {
+        printf("No eligible student found.\n");
+    }
+}
+
+void sort() {
+    int i, j;
+    for (i = 0; i < count - 1; i++) {
+        for (j = i + 1; j < count; j++) {
+            if (strcmp(students[i].clas, students[j].clas) > 0 || 
+               (strcmp(students[i].clas, students[j].clas) == 0 && students[i].totalScore < students[j].totalScore)) {
+                Student temp = students[i];
+                students[i] = students[j];
+                students[j] = temp;
+            }
+        }
+    }
+    printf("Students sorted successfully.\n");
+    output();
+}
+
+void output() {
+    if (count == 0) {
+        printf("No students to display.\n");
+        return;
+    }
+    int i;
+    for (i = 0; i < count; i++) {
+        printf("%s %s %s %.1f %.1f %.1f %.1f\n", students[i].id, students[i].clas, students[i].name,
+               students[i].score1, students[i].score2, students[i].score3, students[i].totalScore);
+    }
+}