#define _CRT_SECURE_NO_WARNINGS
#define N 20
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
struct date
{
    int day, month, year;
};
struct lecturer
{
    char *name;
    struct date birthday;
    int num_of_courses;
    char **courses;
};
void Course_Lectures(struct lecturer *arr1, char *name, int size)
{
    int i, j;
    int i_course, j_course;
    for (i = 0; i < size; i++)
    {
        for (j = 0; j < arr1[i].num_of_courses; j++)
        {
            if (strcmp(name, arr1[i].courses[j]) == 0)
            {
                puts(arr1[i].name);
            }
        }
    }

}
void common(struct lecturer *arr1, char *name1, char *name2, int size)
{
    int i, j;
    int i_name, j_name;
    for (i = 0; i < size; i++)
    {
        if (strcmp(name1, arr1[i].name) == 0)
        {
            i_name = i;
        }
        if (strcmp(name2, arr1[i].name) == 0)
        {
            j_name = i;
        }
    }
    for (i = 0; i < arr1[i_name].num_of_courses; i++)
    {
        for (j = 0; j < arr1[j_name].num_of_courses; j++)
            if ((strcmp(arr1[i_name].courses[i], arr1[j_name].courses[j])) == 0)
                printf(arr1[i_name].courses[i]);
    }
}
void old(int day,int month,int year,struct lecturer *arr1, int size)
{
    int i, j;
    for (i = 0; i < size; i++)
    {
        if (arr1[i].birthday.year<year)
        {
            puts(arr1[i].name);
        }
        else if (arr1[i].birthday.year =year)
        {
            if (arr1[i].birthday.month = month)
            {
                if (arr1[i].birthday.day <= day)
                {
                    puts(arr1[i].name);
                }
            }
        }
    }
}
int main()
{
    struct lecturer *data = NULL;
    int day,month,year;
    int size, i, j;
    char name[N], name1[N], name2[N], NameCourse[N];
    printf("enter please the number of the lectrures :\n ");
    scanf("%d", &size);
    data = (struct lecturer*)malloc(size * sizeof(struct lecturer));
    if (data == NULL)
    {
        printf("error \n");
        return 0;
    }
    for (i = 0; i < size; i++)
    {
        printf("enter the name of the prof:\n");
        scanf("%s", name);
        data[i].name = (char*)malloc((strlen(name) + 1) * sizeof(char));
        if (data[i].name == NULL)
        {
            printf("memory error \n");
            // Oh look memory leak. Free your things!
            return 0;
        }
        for (j = 0; j < strlen(name); j++)
        {
            data[i].name[j] = name[j];
        }
        data[i].name[j] = '\0';

        printf("please enter the birthday of the prof :\n");
        scanf("%d%d%d", &data[i].birthday.day, &data[i].birthday.month, &data[i].birthday.year);
        printf("enter the number of courses of the prof :\n");
        scanf("%d", &data[i].num_of_courses);
        data[i].courses = (char**)malloc(data[i].num_of_courses * sizeof(char*));
        for (j = 0; j<data[i].num_of_courses; j++)
        {
            data[i].courses[j] = (char*)malloc(N * sizeof(char));
            if (data[i].courses[j] == NULL)
            {
                printf("memory error \n");
                // Oh look memory leak. Free your things!
                return 0;
            }
            printf("enter the name of the course :\n");
            scanf("%s", data[i].courses[j]);
        }
    }

    printf("Done inputting lecturers, now inputting courses:\n");
    printf("enter the name of the course :\n");
    scanf("%s", NameCourse);
    Course_Lectures(data,NameCourse, size);
    printf("\n");
    printf("enter names of two profs\n");
    scanf("%s", name1);
    scanf("%s", name2);
    common(data, name1, name2, size);
    printf("\n");
    printf("enter the date after which the prof was born");
    scanf("%d%d%d",&day,&month, &year);
    old(day,month,year, data, size);
    for (i = 0; i < size; i++)
    {
        for (j = 0; j<data[i].num_of_courses; j++)
            free(data[i].courses[j]);
        free(data[i].courses);
    }
    free(data);
    return 0;

}