box-o-sand/curses-practice/JustForFun/hanoi.c

#include <curses.h>

#define POSX 10
#define POSY 5
#define DISC_CHAR '*'
#define PEG_CHAR '#'
#define TIME_OUT 300

typedef struct _peg_struct {
    int n_discs;        /* Number of discs at present     */
    int bottomx, bottomy;    /* bottom x, bottom y co-ord      */
    int *sizes;        /* The disc sizes array        */
}peg;

void init_pegs(peg *p_my_pegs, int n_discs);
void show_pegs(WINDOW *win, peg *p_my_pegs, int n_discs);
void free_pegs(peg *p_my_pegs, int n_discs);
void solve_hanoi(peg *p_my_pegs, int n, int src, int aux, int dst);
void move_disc(peg *p_my_pegs, int n_discs, int src, int dst);
void print_in_middle(int startx, int starty, int width, char *string, WINDOW *win);
void check_usr_response(peg *p_my_pegs, int n_discs);

int store_n_discs;
char *welcome_string = "Enter the number of discs you want to be solved: ";

int main(int argc, char *argv[])
{    int n_discs;
    peg my_pegs[3];

    initscr();    /* Start curses mode         */
    cbreak();    /* Line buffering disabled. Pass on every thing */
    keypad(stdscr, TRUE);
    curs_set(FALSE);

    print_in_middle(0, LINES / 2, COLS, welcome_string, NULL);
    scanw("%d", &n_discs);

    timeout(TIME_OUT);
    noecho();
    store_n_discs = n_discs;

    init_pegs(my_pegs, n_discs);
    show_pegs(stdscr, my_pegs, n_discs);
    solve_hanoi(my_pegs, n_discs, 0, 1, 2);

    free_pegs(my_pegs, n_discs);
    endwin();        /* End curses mode          */
    return 0;
}

void solve_hanoi(peg *p_my_pegs, int n_discs, int src, int aux, int dst)
{    if(n_discs == 0)
        return;
    solve_hanoi(p_my_pegs, n_discs - 1, src, dst, aux);
    move_disc(p_my_pegs, store_n_discs, src, dst);
    show_pegs(stdscr, p_my_pegs, store_n_discs);
    check_usr_response(p_my_pegs, store_n_discs);
    solve_hanoi(p_my_pegs, n_discs - 1, aux, src, dst);
}

void check_usr_response(peg *p_my_pegs, int n_discs)
{    int ch;

    ch = getch(); /* Waits for TIME_OUT milliseconds */
    if(ch == ERR)
        return;
    else
        if(ch == KEY_F(1))
        {    free_pegs(p_my_pegs, n_discs);
            endwin();
            exit(0);
        }
}

void move_disc(peg *p_my_pegs, int n_discs, int src, int dst)
{    int temp, index;

    --p_my_pegs[src].n_discs;
    index = 0;
    while(p_my_pegs[src].sizes[index] == 0 && index != n_discs)
        ++index;
    temp = p_my_pegs[src].sizes[index];
    p_my_pegs[src].sizes[index] = 0;

    index = 0;
    while(p_my_pegs[dst].sizes[index] == 0 && index != n_discs)
        ++index;
    --index;
    p_my_pegs[dst].sizes[index] = temp;
    ++p_my_pegs[dst].n_discs;
}

void init_pegs(peg *p_my_pegs, int n_discs)
{    int size, temp, i;

    p_my_pegs[0].n_discs = n_discs;

    /* Allocate memory for size array
     * atmost the number of discs on a peg can be n_discs
      */
    for(i = 0; i < n_discs; ++i)
        p_my_pegs[i].sizes = (int *)calloc(n_discs, sizeof(int));
    size = 3;
    for(i = 0;i < n_discs; ++i, size += 2)
        p_my_pegs[0].sizes[i] = size;

    temp = (p_my_pegs[0].sizes[n_discs - 1] / 2);
     p_my_pegs[0].bottomx = POSX + 1 + temp;
    p_my_pegs[0].bottomy = POSY + 2 + n_discs;

     p_my_pegs[1].bottomx = p_my_pegs[0].bottomx + 2 + 2 * temp;
    p_my_pegs[1].bottomy = POSY + 2 + n_discs;

     p_my_pegs[2].bottomx = p_my_pegs[1].bottomx + 2 + 2 * temp;
    p_my_pegs[2].bottomy = POSY + 2 + n_discs;
}

void show_pegs(WINDOW *win, peg *p_my_pegs, int n_discs)
{    int i, j, k, x, y, size;

    wclear(win);
    attron(A_REVERSE);
    mvprintw(24, 0, "Press F1 to Exit");
    attroff(A_REVERSE);
    for(i = 0;i < 3; ++i)
        mvwprintw(    win, p_my_pegs[i].bottomy - n_discs - 1,
                    p_my_pegs[i].bottomx, "%c", PEG_CHAR);
    y = p_my_pegs[0].bottomy - n_discs;
    for(i = 0; i < 3; ++i)    /* For each peg */
    {    for(j = 0; j < n_discs; ++ j)    /* For each row */
        {    if(p_my_pegs[i].sizes[j] != 0)
            {    size = p_my_pegs[i].sizes[j];
                x = p_my_pegs[i].bottomx - (size / 2);
                for(k = 0; k < size; ++k)
                    mvwprintw(win, y, x + k, "%c", DISC_CHAR);
            }
            else
                mvwprintw(win, y, p_my_pegs[i].bottomx, "%c", PEG_CHAR);
            ++y;
        }
        y = p_my_pegs[0].bottomy - n_discs;
    }
    wrefresh(win);
}

void free_pegs(peg *p_my_pegs, int n_discs)
{    int i;

    for(i = 0;i < n_discs; ++i)
            free(p_my_pegs[i].sizes);
}

/* -------------------------------------------------------------*
 * startx = 0 means at present x                 *
 * starty = 0 means at present y                *
 * win = NULL means take stdscr                 *
 * -------------------------------------------------------------*/

void print_in_middle(int startx, int starty, int width, char *string, WINDOW *win)
{    int length, x, y;
    float temp;

    if(win == NULL)
        win = stdscr;
    getyx(win, y, x);
    if(startx != 0)
        x = startx;
    if(starty != 0)
        y = starty;
    if(width == 0)
        width = 80;

    length = strlen(string);
    temp = (width - length)/ 2;
    x = startx + (int)temp;
    mvwprintw(win, y, x, "%s", string);
    refresh();
}