diff --git a/step 7.cpp b/step 7.cpp
new file mode 100644
index 0000000..cb9c78d
--- /dev/null
+++ b/step 7.cpp	
@@ -0,0 +1,270 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+int studentMember = 7;
+
+typedef struct storeInformation
+{
+    char stus[100];
+    int classes;
+    char names[100];
+    double mathGrade;
+    double physicsGrade;
+    double englishGrade;
+    int boolNew;
+} stu;
+
+stu studentInformation[100] = {
+    { "10001", 11, "Zhang", 99.5, 88.5, 89.5, 0 },
+    { "10002", 12, "Yang", 77.9, 56.5, 87.5, 0 },
+    { "10003", 11, "Liang", 92.5, 99.0, 60.0, 0 },
+    { "10004", 11, "Cai", 89.6, 56.9, 90.5, 0 },
+    { "10005", 14, "Fu", 55.6, 67.9, 98.9, 0 },
+    { "10006", 12, "Mao", 22.1, 45.9, 99.2, 0 },
+    { "10007", 13, "Zhan", 35.6, 67.9, 88.0, 0 }
+};
+
+void input(int i) {
+    scanf("%s", studentInformation[i].stus);
+    scanf("%d", &studentInformation[i].classes);
+    scanf("%s", studentInformation[i].names);
+    scanf("%lf", &studentInformation[i].mathGrade);
+    scanf("%lf", &studentInformation[i].physicsGrade);
+    scanf("%lf", &studentInformation[i].englishGrade);
+}
+
+void inputStudentInformation(int n) {
+    for (int i = 0; i < n; i++) {
+        input(i);
+        studentMember++;
+        studentInformation[i].boolNew = 0;
+        printf("One student has been input!\n");
+    }
+}
+
+void insertedNew() {
+    int i = studentMember;
+    input(i);
+    studentMember++;
+    studentInformation[i].boolNew = 1;
+    printf("One student has been input!\n");
+}
+
+void informationClear(char a[100]) {
+    int i = 0;
+    for (i = 0; i < studentMember; i++) {
+        if (strcmp(a, studentInformation[i].stus) == 0 || strcmp(a, studentInformation[i].names) == 0) {
+            memset(&studentInformation[i], 0, sizeof(studentInformation[i]));
+        }
+    }
+}
+
+void sortStudents() {
+    for (int i = 0; i < studentMember - 1; i++) {
+        for (int j = 0; j < studentMember - i - 1; j++) {
+            double totalScoreJ = studentInformation[j].mathGrade + studentInformation[j].physicsGrade + studentInformation[j].englishGrade;
+            double totalScoreJ1 = studentInformation[j + 1].mathGrade + studentInformation[j + 1].physicsGrade + studentInformation[j + 1].englishGrade;
+
+            if (studentInformation[j].classes > studentInformation[j + 1].classes ||
+                (studentInformation[j].classes == studentInformation[j + 1].classes && totalScoreJ < totalScoreJ1)) {
+                stu temp = studentInformation[j];
+                studentInformation[j] = studentInformation[j + 1];
+                studentInformation[j + 1] = temp;
+            }
+        }
+    }
+    printf("Students have been sorted!\n");
+}
+
+void printStudentOriginalScore() {
+    sortStudents();
+    int classs = 0;
+    for (int i = 0; i < studentMember; i++) {
+        if (studentInformation[i].classes != 0) {
+            if (studentInformation[i].classes != classs) {
+                printf("%d  %s  %s  %.1f  %.1f  %.1f  %s\n",
+                    studentInformation[i].classes,
+                    studentInformation[i].stus,
+                    studentInformation[i].names,
+                    studentInformation[i].mathGrade,
+                    studentInformation[i].physicsGrade,
+                    studentInformation[i].englishGrade,
+                    studentInformation[i].boolNew == 0 ? "" : studentInformation[i].boolNew == 1 ? "inserted" : "modified");
+            }
+            else {
+                printf("   %s  %s  %.1f  %.1f  %.1f  %s\n",
+                    studentInformation[i].stus,
+                    studentInformation[i].names,
+                    studentInformation[i].mathGrade,
+                    studentInformation[i].physicsGrade,
+                    studentInformation[i].englishGrade,
+                    studentInformation[i].boolNew == 0 ? "" : studentInformation[i].boolNew == 1 ? "inserted" : "modified");
+            }
+            classs = studentInformation[i].classes;
+            studentInformation[i].boolNew = 0;
+        }
+    }
+
+}
+
+void modifyStudent() {
+    char a[10];
+    printf("Are you sure(yes/no)");
+    scanf("%s", &a);
+    if ((strcmp(a, "yes")) == 0) {
+        char stusToModify[10];
+        printf("Enter the student number to modify, followed by new data ( 10001 2 Kobe 59 59 59):\n");
+        scanf("%s", stusToModify);
+
+        int found = 0;
+        for (int i = 0; i < studentMember; i++) {
+            if (strcmp(studentInformation[i].stus, stusToModify) == 0) {
+                found = 1;
+                scanf("%d %s %lf %lf %lf",
+                    &studentInformation[i].classes,
+                    studentInformation[i].names,
+                    &studentInformation[i].mathGrade,
+                    &studentInformation[i].physicsGrade,
+                    &studentInformation[i].englishGrade);
+                studentInformation[i].boolNew = 2;
+                printf("Student data modified successfully!\n");
+                break;
+            }
+        }
+        if (!found) {
+            printf("Student with number %s not found.\n", stusToModify);
+        }
+    }
+}
+void queryByClassRange(int startClass, int endClass) {
+    printf("Students in classes %d to %d:\n", startClass, endClass);
+    for (int i = 0; i < studentMember; i++) {
+        if (studentInformation[i].classes >= startClass && studentInformation[i].classes <= endClass) {
+            printf("%s %d %s %.1f %.1f %.1f\n",
+                studentInformation[i].stus, studentInformation[i].classes, studentInformation[i].names,
+                studentInformation[i].mathGrade, studentInformation[i].physicsGrade, studentInformation[i].englishGrade);
+        }
+    }
+}
+
+void queryByIDRange(char startID[10], char endID[10]) {
+    printf("Students with IDs %s to %s:\n", startID, endID);
+    for (int i = 0; i < studentMember; i++) {
+        if (strcmp(studentInformation[i].stus, startID) >= 0 &&
+            strcmp(studentInformation[i].stus, endID) <= 0) {
+            printf("%s %d %s %.1f %.1f %.1f\n",
+                studentInformation[i].stus, studentInformation[i].classes, studentInformation[i].names,
+                studentInformation[i].mathGrade, studentInformation[i].physicsGrade, studentInformation[i].englishGrade);
+        }
+    }
+}
+
+void queryByNamePrefix(const char* prefix) {
+    printf("Students with names starting with %s:\n", prefix);
+    for (int i = 0; i < studentMember; i++) {
+        if (strncmp(studentInformation[i].names, prefix, strlen(prefix)) == 0) {
+            printf("%s %d %s %.1f %.1f %.1f\n",
+                studentInformation[i].stus, studentInformation[i].classes, studentInformation[i].names,
+                studentInformation[i].mathGrade, studentInformation[i].physicsGrade, studentInformation[i].englishGrade);
+        }
+    }
+}
+
+void queryByTotalScore(double threshold) {
+    printf("Students with total score >= %.1f:\n", threshold);
+    for (int i = 0; i < studentMember; i++) {
+        double totalScore = studentInformation[i].mathGrade + studentInformation[i].physicsGrade + studentInformation[i].englishGrade;
+        if (totalScore >= threshold) {
+            printf("%s %d %s %.1f %.1f %.1f\n",
+                studentInformation[i].stus, studentInformation[i].classes, studentInformation[i].names,
+                studentInformation[i].mathGrade, studentInformation[i].physicsGrade, studentInformation[i].englishGrade);
+        }
+    }
+}
+
+void queryByClassAndIDRange(int classNum, char startID[10], char endID[10]) {
+    printf("Students in class %d with IDs %s to %s:\n", classNum, startID, endID);
+    for (int i = 0; i < studentMember; i++) {
+        if (studentInformation[i].classes == classNum &&
+            strcmp(studentInformation[i].stus, startID) >= 0 &&
+            strcmp(studentInformation[i].stus, endID) <= 0) {
+            printf("%s %d %s %.1f %.1f %.1f\n",
+                studentInformation[i].stus, studentInformation[i].classes, studentInformation[i].names,
+                studentInformation[i].mathGrade, studentInformation[i].physicsGrade, studentInformation[i].englishGrade);
+        }
+    }
+}
+
+void handleInput() {
+    int queryType;
+    printf("Enter query type (1-5): ");
+    scanf("%d", &queryType);
+
+    if (queryType == 1) {
+        int startClass, endClass;
+        printf("Enter class range (start end): ");
+        scanf("%d %d", &startClass, &endClass);
+        queryByClassRange(startClass, endClass);
+    }
+    else if (queryType == 2) {
+        char startID[10], endID[10];
+        printf("Enter ID range (start end): ");
+        scanf("%s %s", startID, endID);
+        queryByIDRange(startID, endID);
+    }
+    else if (queryType == 3) {
+        char prefix[10];
+        printf("Enter name prefix: ");
+        scanf("%s", prefix);
+        queryByNamePrefix(prefix);
+    }
+    else if (queryType == 4) {
+        double threshold;
+        printf("Enter total score threshold: ");
+        scanf("%lf", &threshold);
+        queryByTotalScore(threshold);
+    }
+    else if (queryType == 5) {
+        int classNum;
+        char startID[10], endID[10];
+        printf("Enter class and ID range (class startID endID): ");
+        scanf("%d %s %s", &classNum, startID, endID);
+        queryByClassAndIDRange(classNum, startID, endID);
+    }
+    else {
+        printf("Invalid query type.\n");
+    }
+}
+
+void manage() {
+    printf("                              1.Input\n");
+    printf("                              2.Output\n");
+    printf("                              3.Order\n");
+    printf("                              4.Quit\n");
+    char keywords;
+    keywords = getchar();
+    switch (keywords) {
+    case 'i':
+        printf("Please input info of the three students\n");
+        inputStudentInformation(3);
+        break;
+    case 'o':
+        printf("You are trying to Output info\n");
+        break;
+    case 'm':
+        printf("You are trying to Make things ordered\n");
+        break;
+    case 'q':
+        printf("You are about to Quit\n");
+        break;
+    default:
+        printf("Wrong input\n");
+        break;
+    }
+}
+
+int main() {
+    handleInput();
+    return 0;
+}
\ No newline at end of file