OS_HW1

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

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


void swap(int *x, int *y)
{
    int t;
    t = *x;
    *x = *y;
    *y = t;
//    *x = *x + *y;
//    *y = *x - *y;
//    *x = *x - *y;
};

void reverse(int *array, size_t size)
{
    for (int i = 0; i < size / 2; ++i)
    {
        swap(&array[i], &array[size - i - 1]);
    }
};

void printArray(int *array, size_t size)
{

    for (int i = 0; i < size; ++i)
    {
        printf("%d ", array[i]);
    }
};


void printMatrix(int **matrix, size_t r, size_t c)
{
    for (int i = 0; i < r; ++i)
    {
        for (int j = 0; j < c; ++j)
        {
            printf("%d\t", matrix[i][j]);
        }
        printf("\n");
    }

};


void transpose(int **matrix, int **t, size_t r, size_t c)
{
    for (int i = 0; i < c; ++i)
    {
        for (int j = 0; j < r; ++j)
        {
            t[i][j] = matrix[j][i];
        }
    }
};

void listAppend(struct Node **head, int value)
{
    struct Node *newNode = (struct Node *) malloc(sizeof(struct Node));
    struct Node *last = *head;

    newNode->value = value;
    newNode->next = NULL;

//    if empty
    if (*head == NULL)
    {
        *head = newNode;
        return;
    }

    while (last->next != NULL)
        last = last->next;

    last->next = newNode;


}

void listPrint(struct Node *list)
{
    while (list != NULL)
    {
        printf("%d ", list->value);
        list = list->next;
    }
}

void listReverse(struct Node **list)
{
    struct Node *previous = NULL;
    struct Node *current = *list;
    struct Node *next = NULL;

    while (current != NULL)
    {
        next = current->next;
        current->next = previous;
        previous = current;
        current = next;
    }
    *list = previous;
}


void task1()
{
    int a, b;
    scanf("%d %d", &a, &b);
    swap(&a, &b);
    printf("x: %d y: %d", a, b);

};

void task2()
{
    int n;
    int *arr;
    scanf("%d", &n);
    arr = malloc(n * sizeof(int));
    for (int i = 0; i < n; ++i)
    {
        int input;
        scanf("%d", &input);
        arr[i] = input;
    }

    reverse(arr, n);
    printArray(arr, n);

    free(arr);


}

void task3()
{
    int r, c;
    scanf("%d %d", &r, &c);

    int **matrix = malloc(r * sizeof(int *));
    for (int i = 0; i < r; ++i)
    {
        matrix[i] = malloc(c * sizeof(int));
    }
    for (int i = 0; i < r; ++i)
    {
        for (int j = 0; j < c; ++j)
        {
            int input;
            scanf("%d", &input);
            matrix[i][j] = input;

        }
    }

    int **t = malloc(c * sizeof(int *));
    for (int i = 0; i < c; ++i)
    {
        t[i] = malloc(r * sizeof(int));
    }


    transpose(matrix, t, r, c);

    printMatrix(t, c, r);

    free(matrix);
    free(t);
}

void task4()
{
    int input;
    struct Node *head = NULL;
    scanf("%d", &input);

    while (input != 0)
    {
        listAppend(&head, input);
        scanf("%d", &input);
    }
    listReverse(&head);
    listPrint(head);
}

int main()
{
    //task1();
    //task2();
    //task3();
    //task4();
    return 0;
}