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

struct addinf {
	char date[10]; // дата зачисления
	float GradePoint;  //средний балл
};

struct info {
	int NumOfBook; // номер зачётки
	char *surname;
	addinf inf;
};

void Enterinf();
void findstudents(int n, struct info *students, char sfind[]);
void RemoveStudents(int n, struct info *students, int num);

int main() {
	Enterinf();
	rewind(stdin);
	_getch();
	return 0;
}

void Enterinf() {
	int n, num, size = 0;
	struct info *students;
	char c, *FindStudent;
	printf(" Enter number of students: ");
	while (!scanf_s("%d", &n) || n < 1) {
		printf("	 wrong input, try again\n");
		rewind(stdin);
	}
	while (!(students = (struct info*)malloc(n * sizeof(struct info)))) {
		printf("Allocating error");
		_getch();
		exit(1);
	}
	for (int i = 0; i < n; i++) {
		printf(" Student %d\n     ", i + 1);
		printf("Number of record book: ");
		while (!scanf_s("%d", &students[i].NumOfBook) || students[i].NumOfBook < 0) {
			printf("	 wrong input, try again: ");
			rewind(stdin);
		}
		rewind(stdin);
		printf("     Student's surname: ");
		students[i].surname = (char*)malloc(sizeof(char));
		while ((c = getchar()) != '\n') {
			size++;
			students[i].surname = (char*)realloc(students->surname, (1 + size) * sizeof(char));
			students[i].surname[size - 1] = c;
			students[i].surname[size] = '\0';
		}
		size = 0;
		rewind(stdin);
		printf("     Enrollment date (DD.MM.YYYY) : ");
		while (!scanf_s("%s", &students[i].inf.date) || students[i].inf.date[2] != '.' || students[i].inf.date[5] != '.') {
			printf("\n	 Incorrect date, try again: ");
			rewind(stdin);
		}

		printf("     Grade point average: ");
		while (!scanf_s("%f", &students[i].inf.GradePoint) || students[i].inf.GradePoint > 10 || students[i].inf.GradePoint < 0) {
			printf("\n wrong gpa, try again");
			rewind(stdin);
		}
	}
	printf("\n Enter student's surname, who you want to find: ");
	size = 0;
	FindStudent = (char*)malloc(sizeof(char));
	rewind(stdin);
	while ((c = getchar()) != '\n') {
		size++;
		FindStudent = (char*)realloc(FindStudent, (1 + size) * sizeof(char));
		FindStudent[size - 1] = c;
		FindStudent[size] = '\0';
	}
	printf("\n Enter a number of record book to delete: ");
	while (!scanf_s("%d", &num)) {
		printf("\nwrong input, try again: ");
		rewind(stdin);
	}
	findstudents(n, students, FindStudent);
	RemoveStudents(n, students, num);
	free(students);
}
void findstudents(int n, struct info* students, char FindStudent[]) {
	int i;
	for (i = 0; i < n; i++) {
		if (strcmp(students[i].surname, FindStudent) == 0) {
			printf("\n find a student:\n Number of RB: %d\n Surname %s\n Enrollment date: %s\n GPA: %.1f",
				students[i].NumOfBook, students[i].surname, students[i].inf.date, students[i].inf.GradePoint);
		}
	}
}
void RemoveStudents(int n, struct info *students, int num) {
	int i, size;
	size = n;
	for (i = 0; i < n; i++) {
		if (students[i].NumOfBook < num) {
			students[i].NumOfBook = students[i + 1].NumOfBook;
			size--;
		}
	}
	if (size < 0) {
	students = (struct info*)realloc(students, size * sizeof(struct info));
	printf("\n updated list\n");
		for (i = 0; i < size; i++) {
			printf("%s - %d\n", students[i].surname, students[i].NumOfBook);
		}
	} else {
		printf("no one find");
	}
}