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

struct course {
    char CN [20];
    double avg;
    struct student *sh;
    struct course *next;
};

struct student {
    char SN[20];
    int age;
    char ID[11];
    double score[4];
    struct student *next;
};



struct student* CreateStudentList (){  // יצירת רשימה מקושרת של סטודנטים
    struct student *p, *head=NULL, *tail;
    int i;

    while(1){
        printf("Any key to add student, esc to finish: \n");
        flushall();
        if (getch() == 27) break;

        p= (struct student *)malloc (sizeof(struct student));
        printf("  Enter student name: ");
        gets (p->SN);
        printf("  Enter student age: ");
        scanf("%d",&p->age);
        flushall();
        printf("  Enter student ID: ");
        gets(p->ID);
        for(i=0;i<4;i++){
            printf("  %d  Enter score: ",i+1);
            scanf("%lf",&p->score[i]);
        }


        if (head ==NULL){
            head = tail = p;
            p->next = NULL;
        }
        else {
            tail -> next = p;
            p-> next = NULL;
            tail = p;
        }

    }
    return head;
}
///
struct course* CreateCourseList (){  //  רשימה מקושרת של קורסים שמקשרים אל רשימות סטודנטים
    struct course *p, *head=NULL, *tail;
    struct student *q;
    int i,h;
    double avg=0.0;

    while(1){
        printf("Press esc to exit, any key to continue and create a new course: \n");
        flushall();
        if (getch() == 27) break;

        p = (struct course *)malloc (sizeof(struct course));
        printf("\nEnter course name: ");
        gets (p->CN);

        if (head == NULL){
            head = tail = p;
            p->next = NULL;
        }
        else {
            tail -> next = p;
            p-> next = NULL;
            tail = p;
        }

        p-> sh = CreateStudentList ();
        if (!p->sh) continue; // ==         if (p-> sh==NULL) continue;


        p->avg = 0.0;
        for(q=p->sh,h=0; q ;q=q->next,avg=0.0,h++){

            for(i=0;i<4;i++)
                avg += (q->score[i]);

            avg = avg/4.0;
            p->avg +=avg;
        }
        p->avg = (p->avg)/h;

        printf("There is: %d students in the %s course \n",h,p->CN);
        printf("The avg score of all the students in the %s course is: %.3lf \n\n\n",p->CN,p->avg);

    }
    return head;
}



/// הדפסה:
void PrintCourseAND_Students(struct course* head) {
    struct student *p;
    int i,b;

    for ( ;head ;head=head->next){
        printf("\n\nCourse name: %s \n",head->CN);
        p=head->sh;
        if (p==NULL) printf("  There is no students in this course\n");

        for(i=1; p ;p=p->next,i++){
            printf("\n%d Student name: %s\n",i,p->SN);
            printf ("  Student age: %d\n",p->age);
            printf("  Student ID: %s\n",p->ID);
            for(b=0;b<4;b++){
                printf("   T%d  score: %.1lf\n",b+1,p->score[b]);
            }
        }
    }
}

/// מציאת הסטודנט הכי טוב בכל מקצוע:
void BestStudent(struct course* head){
    struct student *p,*q;
    int i;
    double avg_p,avg_q;

    for (avg_q=0;head ;head=head->next){
        printf("\n\nCourse name: %s \n",head->CN);
        p=head->sh;
        if (p==NULL) { printf("  There is no students in this course\n"); continue;}

        for(q=p; p ;p=p->next){ // מצביע על הסטודנט הכי טוב q
            for(i=0,avg_p=0;i<4;i++){
                avg_p += p->score[i];
            }
            avg_p = avg_p/4;
            if(avg_q<avg_p){
                q=p; avg_q=avg_p;
            }
        }

        printf("\n  The best student: %s\n",q->SN);
        printf("  age: %d\n",q->age);
        printf("  ID: %s\n",q->ID);
        for(i=0;i<4;i++){
            printf("   T%d  score: %.1lf\n",i+1,q->score[i]);
        }

    }

}

/// סטודנטים שנכשלו
void FailStudent(struct course* head){
    struct student *p;
    int i,b;
    double avg_p;

    for (;head ;head=head->next){
        printf("\n\nCourse name: %s \n",head->CN);
        p=head->sh;
        if (p==NULL){
            printf("  There is no students in this course\n");
            continue;
        }

        for(b=0; p ;p=p->next){
            for(i=0,avg_p=0;i<4;i++)
                avg_p += p->score[i];
            avg_p = avg_p/4;

            if(avg_p<55)
                printf("%d fail student: %s\n",++b,p->SN);
            if (b==0)
                printf("There is no fail students in this course");
        }
    }
}






void main(){
    struct course *p;
    p = CreateCourseList ();
    // PrintCourseAND_Students(p);
    // BestStudent(p);
    // FailStudent(p);

}