#define OP_BACKSPACE    1
#define OP_COPY         2
#define OP_MOVE         3
#define OP_DELETE       4
#define OP_PASTE        5
#define OP_UNDO         6
#define OP_REDO         7
#define OP_INSERT       8

void applyop(int idx, int n, FILE *f, NODE **h, int v[8], int pos)
{
    int i;
    char buff[64];

    for (i = 0; i < n; i++)
    {
        fgets(buff, 64, f);

        if (i != idx)
            continue;

        switch (v[i])
        {
            case OP_BACKSPACE:
            {
                // aplici backspace cu parametrul pos si h
            }
            case OP_PASTE:
            {
                // la fel
            }
            case OP_MOVE:
            {
                x = atoi(buff + 5);

                // aplici move cu parametrii x, h, pos
            }
            // etc
        }
    }
}

fscanf(f, "%d", &n);
getchar();

for(i = 0; i < n; i++)
{
    fgets(buff, 64, f);

    if (!strcmp(buff, "backspace"))
        v[i] = OP_BACKSPACE;

    else if (!strcmp(buff, "undo"))
        v[i] = OP_UNDO;

    else if (!strcmp(buff, "redo"))
        v[i] = OP_REDO;

    else if (!strcmp(buff, "paste"))
        v[i] = OP_PASTE;

    else if (!strstr(buff, "copy"))
        v[i] = OP_COPY;

    else if (!strstr(buff, "delete"))
        v[i] = OP_DELETE;

    else if (!strstr(buff, "insert"))
        v[i] = OP_INSERT;

    else
        v[i] = OP_MOVE;
}

for (i = 0, undo = -1; i < n; i++)
{
    if (i+1 < n)
    {
        if (v[i+1] == OP_UNDO)
            undo = i;
    }

    if (undo == i)
        continue;

    if (v[i] == OP_REDO)
    {
        if (undo != -1)
        {
            // aplica operatia undo.
            undo = -1;
        }
        else
            printf("Nu a fost gasita nicio operatie undo precedenta!");
    }
}