#define _CRT_SECURE_NO_WARNINGS

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

struct Node
{
	int data;
	struct Node* next;
};

struct Node* first = NULL;

void printList()
{
	struct Node* ptr = first;
	while (ptr != NULL)
	{
		printf("(%d)->", ptr->data);
		ptr = ptr->next;
	}
	printf("NULL\n");
}
void addToHead(int value)
{
	struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));

	newNode->next = first;
	newNode->data = value;

	first = newNode;
}
int deleteFromHead()
{
	int value = first->data;
	struct Node* delNode = first;
	first = first->next;
	free(delNode);
	return value;
}
int contains(int value)
{
	struct Node* ptr = first;
	while (ptr != NULL)
	{
		if (ptr->data == value)
		{
			return 1;
		}
		ptr = ptr->next;
	}
	return 0;
}
void clearList()
{
	while (first != NULL)
	{
		struct Node* delNode = first;
		first = first->next;
		free(delNode);
	}
}
int sum()
{
	struct Node* ptr = first;
	int s = 0;
	while (ptr != NULL)
	{
		s += ptr->data;
		ptr = ptr->next;
	}
	return s;
}
int evenCount()
{
	struct Node* ptr = first;
	int count = 0;
	while (ptr != NULL)
	{
		if (ptr->data % 2 == 0)
		{
			count++;
		}
		ptr = ptr->next;
	}
	return count;
}
void oddsX10()
{
	struct Node* ptr = first;
	while (ptr != NULL)
	{
		if (ptr->data % 2 != 0)
		{
			ptr->data = ptr->data * 10;
		}
		ptr = ptr->next;
	}
}
void elementIx100(int i)
{
	struct Node* ptr = first;
	int index = 0;
	while (ptr != NULL)
	{
		if (index == i)
		{
			ptr->data = ptr->data * 100;
			return;
		}
		ptr = ptr->next;
		index++;
	}
}
void elementLeftIx10(int i)
{
	struct Node* ptr = first;
	int index = 0;
	while (ptr != NULL)
	{
		if (index < i)
		{
			ptr->data = ptr->data * 10;
		}
		index++;
		ptr = ptr->next;
	}
}
void Task1()
{
	printList();
	addToHead(6400);
	addToHead(400);
	addToHead(200);
	addToHead(400);
	printList();

	printf("contains(100) = %d\n", contains(100));
	printf("contains(100) = %d\n", contains(150));
	printf("contains(100) = %d\n", contains(200));

	clearList();
	printList();

	printf("contains(100) = %d\n", contains(100));
	printf("contains(100) = %d\n", contains(150));
	printf("contains(100) = %d\n", contains(200));
	{
		int x;
		scanf("%d", &x);
	}
}
void Task2()
{
	printList();
	addToHead(1);
	addToHead(3);
	addToHead(6);
	addToHead(9);
	printList();

	printf("sum = %d\n", sum());

	clearList();
	printList();
	printf("sum = %d\n", sum());
	{
		int x;
		scanf("%d", &x);
	}
}
void Task3()
{
	printList();

	addToHead(1);
	addToHead(3);
	addToHead(6);
	addToHead(8);
	printList();

	printf("even numbers = %d\n", evenCount());

	clearList();
	printList();
	printf("even numbers = %d\n", evenCount());
	{
		int x;
		scanf("%d", &x);
	}
}
void Task4()
{
	printList();

	addToHead(1);
	addToHead(3);
	addToHead(6);
	addToHead(8);
	printList();

	oddsX10();
	printList();

	clearList();
	printList();
	{
		int x;
		scanf("%d", &x);
	}
}
void Task5()
{
	printList();

	addToHead(1);
	addToHead(3);
	addToHead(6);
	addToHead(8);
	printList();

	elementIx100(0);
	printList();

	elementIx100(2);
	printList();

	elementIx100(0);
	printList();

	{
		int x;
		scanf("%d", &x);
	}
}
void Task6()
{
	printList();

	addToHead(1);
	addToHead(3);
	addToHead(6);
	addToHead(8);
	printList();

	elementLeftIx10(1);
	printList();

	elementLeftIx10(2);
	printList();

	elementLeftIx10(4);
	printList();
	{
		int x;
		scanf("%d", &x);
	}
}
void main()
{
	first = NULL;

	Task1();
	clearList();
	Task2();
	clearList();
	Task3();
	clearList();
	Task4();
	clearList();
	Task5();
	clearList();
	Task6();
}