laba8v2.cpp

#include "stdafx.h"
#include "stdlib.h"
#include "locale.h"

struct Unit {
	int key;
	Unit *next;
};
float read_el(char *s = "") {
	int k;
	float r;
	do {
		do {
			printf(s);
			k = scanf_s("%f", &r);
			while (getchar() != '\n');
		} while (k != 1); k = 0;
	} while (r < 0);
	return r;
}
struct Unit * create(Unit **first) {
	//return NULL;
	*first = new Unit;
	printf("ввод элементов структуры|\n");
	(*first)->key = read_el("el: ");
	(*first)->next = NULL;
	Unit *end = *first;
	int flag;
	printf("выход: 0|");
	flag = read_el();
	if (!flag)
		return *first;
	flag = 0;
	do
	{
		end->next = new Unit;
		end = end->next;
		end->key = read_el("el: ");
		end->next = NULL;
		printf("выход: 0|");
		flag = read_el();
	} while (flag);
	return end;
}

void print(Unit *unit) {
	Unit *print = unit;
	while (print) {
		printf("%d -> ", print->key);
		print = print->next;
	}
	printf("NULL\n");
}

void doLast(Unit **first, int x, Unit **end) {

	if ((*end) == NULL || *first == NULL) {
		*first = new Unit;
		(*first)->key = x;
		(*first)->next = NULL;
		*end = *first;
		return;
	}

	if ((*end)->key == x)
		return;

	if ((*first)->next == NULL) {
		(*end)->next = (Unit*)malloc(sizeof(Unit));
		*end = (*end)->next;
		(*end)->key = x;
		(*end)->next = NULL;
		return;
	}

	Unit *unit = *first;

	if (unit->key == x)
	{
		(*end)->next = unit;
		*first = unit->next;
		(*end)->next->next = NULL;
		return;
	}

	while (unit->next)
	{
		if (unit->next->key == x)
		{
		
			(*end)->next = unit->next;
			(*end) = (*end)->next;

			unit->next = (*end)->next;
			(*end)->next = NULL;
			
			return;
		}
		unit = unit->next;
	}

	(*end)->next = (Unit*)malloc(sizeof(Unit));
	*end = (*end)->next;
	(*end)->key = x;
	(*end)->next = NULL;

}
void main()
{
	setlocale(LC_ALL, "rus");
	int x;
	Unit *first = NULL;
	Unit * end = create(&first);
	print(first);
	x = read_el("X: ");
	doLast(&first, x, &end);
	print(first);
}
//удалить и поставить в конец списка