#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct Student {
    char *id;
    char *clas;
    char *name;
    double score1;
    double score2;
    double score3;
    double score;
};

void input(struct Student students[], int *count);
void delete_student(struct Student students[], int *count);
void select_student(struct Student students[], int count);
void order_student(struct Student students[], int count);
void output_student(struct Student students[], int count);
void free_students(struct Student students[], int count);

int main() {
    struct Student students[100];  
    int count = 0; 
    int option;
    do {
        printf("1. input\n2. delete\n3. select\n4. order\n5. output\n6. quit\nplease input your option: ");
        scanf("%d", &option);
        switch (option) {
            case 1:
                input(students, &count);
                break;
            case 2:
                delete_student(students, &count);
                break;
            case 3:
                select_student(students, count);
                break;
            case 4:
                order_student(students, count);
                break;
            case 5:
                output_student(students, count);
                break;
            case 6:
                printf("Exiting the program...\n");
                break;
            default:
                printf("Invalid option, please try again.\n");
        }
    } while (option != 6);

    free_students(students, count);

    return 0;
}

void input(struct Student students[], int *count) {
    char continue_input[5];
    do {
        if (*count >= 100) {
            printf("Maximum number of students reached.\n");
            break;
        }

        students[*count].id = (char *)malloc(sizeof(char) * 10);
        students[*count].clas = (char *)malloc(sizeof(char) * 20);
        students[*count].name = (char *)malloc(sizeof(char) * 20);
        if (students[*count].id == NULL || students[*count].clas == NULL || students[*count].name == NULL) {
            printf("Memory allocation failed.\n");
            exit(1);
        }

        printf("Enter ID, Class, Name, Score1, Score2, Score3: ");
        scanf("%s %s %s %lf %lf %lf", students[*count].id, students[*count].clas, students[*count].name,
              &students[*count].score1, &students[*count].score2, &students[*count].score3);
        students[*count].score = (students[*count].score1 + students[*count].score2 + students[*count].score3) / 3;

        (*count)++;
        printf("Continue input? (yes/no): ");
        scanf("%s", continue_input);
    } while (strcmp(continue_input, "yes") == 0);
}

void delete_student(struct Student students[], int *count) {
    char id[10];
    printf("Enter the ID of the student to delete: ");
    scanf("%s", id);

    for (int i = 0; i < *count; i++) {
        if (strcmp(students[i].id, id) == 0) {
            free(students[i].id);
            free(students[i].clas);
            free(students[i].name);

            for (int j = i; j < *count - 1; j++) {
                students[j] = students[j + 1];
            }
            (*count)--;
            printf("Student with ID %s deleted successfully.\n", id);
            return;
        }
    }
    printf("Student with ID %s not found.\n", id);
}

void select_student(struct Student students[], int count) {
    char id[10];
    printf("Enter the ID of the student to select: ");
    scanf("%s", id);

    for (int i = 0; i < count; i++) {
        if (strcmp(students[i].id, id) == 0) {
            printf("ID: %s, Class: %s, Name: %s, Score1: %.2f, Score2: %.2f, Score3: %.2f, Average Score: %.2f\n",
                   students[i].id, students[i].clas, students[i].name, students[i].score1, students[i].score2, students[i].score3, students[i].score);
            return;
        }
    }
    printf("Student with ID %s not found.\n", id);
}

void order_student(struct Student students[], int count) {
    for (int i = 0; i < count - 1; i++) {
        for (int j = 0; j < count - i - 1; j++) {
            if (students[j].score < students[j + 1].score) {
                struct Student temp = students[j];
                students[j] = students[j + 1];
                students[j + 1] = temp;
            }
        }
    }
    printf("Students ordered by average score.\n");
}

void output_student(struct Student students[], int count) {
    for (int i = 0; i < count; i++) {
        printf("ID: %s, Class: %s, Name: %s, Score1: %.2f, Score2: %.2f, Score3: %.2f, Average Score: %.2f\n",
               students[i].id, students[i].clas, students[i].name, students[i].score1, students[i].score2, students[i].score3, students[i].score);
    }
}
void free_students(struct Student students[], int count) {
    for (int i = 0; i < count; i++) {
        free(students[i].id);
        free(students[i].clas);
        free(students[i].name);
    }
}