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

struct Student {
    char id[20];
    char clas[20];
    char name[20];
    double score1;
    double score2;
    double score3;
    double score;
};

struct Student* students[1000];
int studentCount = 0;

void printMenu() {
    printf("1. Input\n");
    printf("2. Delete\n");
    printf("3. Select\n");
    printf("4. Order\n");
    printf("5. Output\n");
    printf("6. Quit\n");
    printf("Please input your option: ");
}

void inputStudent() {
    char continueInput[4];
    do {
        if (studentCount < 1000) {
            struct Student* student = (struct Student*)malloc(sizeof(struct Student));
            printf("Id: ");
            scanf("%s", student->id);
            
            printf("Class: ");
            scanf("%s", student->clas);
            
            printf("Name: ");
            scanf("%s", student->name);
            
			printf("Score1: ");
            scanf("%lf", &student->score1);
            
			printf("Score2: ");
            scanf("%lf", &student->score2);
            
			printf("Score3: ");
            scanf("%lf", &student->score3);
            
			student->score = student->score1 + student->score2 + student->score3;
            students[studentCount++] = student;
            printf("continue?\n"); 
            scanf("%s", continueInput);
        } else {
            printf("Student database is full!\n");
            break;
        }
    } while (strcmp(continueInput, "yes") == 0);
}

void deleteStudent() {
    char deleteId[20];
    printf("Enter student ID or name to delete: ");
    scanf("%s", deleteId);


    int deleted = 0;
    for (int i = 0; i < studentCount; i++) {
        if (strcmp(students[i]->id, deleteId) == 0 || strcmp(students[i]->name,deleteId)==0) {
            free(students[i]);
            for (int j=i;j<studentCount-1;j++) {
                students[j]=students[j+1];
            }
            studentCount--;
            deleted=1;
            i--;
        }
    }

    if (deleted==0) {
        printf("Student not found.\n");
    
	
	}
}


void selectStudent() {
    char query[20];
    printf("Enter student ID or class to select: ");
    scanf("%s", query);

    int found=0;
    for (int i=0;i<studentCount;i++) {
        if (strcmp(students[i]->id,query)==0||strcmp(students[i]->clas,query)==0) {
            printf("%s, %s, %s, %.1lf, %.1lf, %.1lf, %.1lf\n", students[i]->id, students[i]->clas, students[i]->name, students[i]->score1, students[i]->score2, students[i]->score3, students[i]->score);
            found=1;
        }
    }



    if (found==0) {
        printf("There is no eligible student.\n");
    }
}

void orderStudents() {
    for (int i = 0; i < studentCount; i++) {
        for (int j = i + 1; j < studentCount; j++) {
            if (strcmp(students[i]->clas, students[j]->clas) > 0 || (strcmp(students[i]->clas, students[j]->clas) == 0 && students[i]->score < students[j]->score)) {
                struct Student* temp = students[i];
                students[i] = students[j];
                students[j] = temp;
            }
        }
    }
}

void outputStudents() {
    for (int i = 0; i < studentCount; i++) {
        printf("%s, %s, %s, %.1lf, %.1lf, %.1lf, %.1lf\n", students[i]->id, students[i]->clas, students[i]->name, students[i]->score1, students[i]->score2, students[i]->score3, students[i]->score);
    }
}

int main() {
    int option;
    do {
        printMenu();
        scanf("%d", &option);
        switch (option) {
            case 1:
                inputStudent();
                break;
            case 2:
                deleteStudent();
                break;
            case 3:
                selectStudent();
                break;
            case 4:
                orderStudents();
                outputStudents();
                break;
            case 5:
                outputStudents();
                break;
            case 6:
  
                break;
            default:
                printf("Invalid option. Please try again.\n");
        }
    } while (option != 6);

    for (int i = 0; i < studentCount; i++) {
        free(students[i]);
    }

    return 0;
}