#defin#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[N], 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[N], char name2[N], 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(struct date old, struct lecturer *arr1, int size)
{
	int i, j;
	for (i = 0; i < size; i++)
	{
		if (arr1[i].birthday.year < old.year)
		{
			puts(arr1[i].name);
		}
		else if (arr1[i].birthday.year = old.year)
		{
			if (arr1[i].birthday.month < old.month)
			{
				if (arr1[i].birthday.day <= old.day)
				{
					puts(arr1[i].name);
				}
			}
		}
	}
}
int main()
{
	struct lecturer *lecturers = NULL;
	int size, i, j;
	struct date old1;
	char name[N], name1[N], name2[N], NameCourse[N];
	printf("enter please the number of the lectrures :\n ");
	scanf("%d", &size);
	lecturers = (struct lecturer*)malloc(size * sizeof(struct lecturer));
	if (lecturers == NULL)
	{
		printf("error \n");
		return 0;
	}
	for (i = 0; i < size; i++)
	{
		printf("enter the name of the prof:\n");
		scanf("%s", name);
		lecturers[i].name = (char*)malloc((strlen(name) + 1) * sizeof(char));
		if (lecturers[i].name == NULL)
		{
			printf("memory error \n");
			// Oh look memory leak. Free your things!
			return 0;
		}
		for (j = 0; j < strlen(name); j++)
		{
			lecturers[i].name[j] = name[j];
		}
		lecturers[i].name[j] = '\0';

		printf("please enter the birthday of the prof :\n");
		scanf("%d%d%d", &lecturers[i].birthday.day, &lecturers[i].birthday.month, &lecturers[i].birthday.year);
		printf("enter the number of courses of the prof :\n");
		scanf("%d", &lecturers[i].num_of_courses);
		lecturers[i].courses = (char**)malloc(lecturers[i].num_of_courses * sizeof(char*));
		for (j = 0; j<lecturers[i].num_of_courses; j++)
		{
			lecturers[i].courses[j] = (char*)malloc(N * sizeof(char));
			if (lecturers[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", lecturers[i].courses[j]);
		}
	}

	printf("enter the name of the course :\n");
	scanf("%s", NameCourse);
	Course_Lectures(lecturers, name, size);
	printf("enter names of two profs\n");
	scanf("%s", name1);
	scanf("%s", name2);
	common(lecturers, name1, name2, size);
	printf("enter the date after which the prof was born");
	scanf("%d%d%d", &old1.day, &old1.month, &old1.year);
	old(old1, lecturers, size);
	free(lecturers);
	for (i = 0; i < size; i++)
	{
	for (j = 0; j<lecturers[i].num_of_courses; j++)
	free(lecturers[i].courses[j]);
	}
	for (i = 0; i < size; i++)
	free(lecturers[i].courses);
	return 0;

}