gistfile1.txt

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

enum dir { N, S, W, E };

static enum dir getcmd(void) {
  int in;
  do {
    in = getchar();
  } while (in == '\n');
  if (in == EOF) {
    printf("see you later\n");
    exit(0);
  }
  switch (in) {
  case 'n':
    return N;
  case 's':
    return S;
  case 'w':
    return W;
  case 'e':
    return E;
  }
  printf("invalid command -- game over man\n");
  exit(0);
}

static void win(void) {
  printf("you won\n");
  assert(0);
}

/*      6 7 8 9 a <- finish
 *      5
 *      4 3 2   d
 *          1 b c
 * start -> 0   e
 *              f
 */

static int room = 0;

#ifdef FUNCS

static void room0(enum dir d) {
  if (d == N)
    room = 1;
}
static void room1(enum dir d) {
  if (d == N)
    room = 2;
  if (d == S)
    room = 0;
  if (d == E)
    room = 0xb;
}
static void room2(enum dir d) {
  if (d == W)
    room = 3;
  if (d == S)
    room = 1;
}
static void room3(enum dir d) {
  if (d == W)
    room = 4;
  if (d == E)
    room = 2;
}
static void room4(enum dir d) {
  if (d == N)
    room = 5;
  if (d == E)
    room = 3;
}
static void room5(enum dir d) {
  if (d == N)
    room = 6;
  if (d == S)
    room = 4;
}
static void room6(enum dir d) {
  if (d == S)
    room = 5;
  if (d == E)
    room = 7;
}
static void room7(enum dir d) {
  if (d == W)
    room = 6;
  if (d == E)
    room = 8;
}
static void room8(enum dir d) {
  if (d == W)
    room = 7;
  if (d == E)
    room = 9;
}
static void room9(enum dir d) {
  if (d == W)
    room = 8;
  if (d == E)
    room = 0xa;
}
static void roomb(enum dir d) {
  if (d == E)
    room = 0xc;
  if (d == W)
    room = 1;
}
static void roomc(enum dir d) {
  if (d == W)
    room = 0xb;
  if (d == N)
    room = 0xd;
  if (d == S)
    room = 0xe;
}
static void roomd(enum dir d) {
  if (d == S)
    room = 0xc;
}
static void roome(enum dir d) {
  if (d == N)
    room = 0xc;
  if (d == S)
    room = 0xf;
}
static void roomf(enum dir d) {
  if (d == N)
    room = 0xe;
}

#else

static const int map[16][4] = {
    {1, -1, -1, -1},     // 0
    {2, 0, -1, 0xb},     // 1
    {-1, 1, 3, -1},      // 2
    {-1, -1, 4, 2},      // 3
    {5, -1, -1, 3},      // 4
    {6, 4, -1, -1},      // 5
    {-1, 5, -1, 7},      // 6
    {-1, -1, 6, 8},      // 7
    {-1, -1, 7, 9},      // 8
    {-1, -1, 8, 0xa},    // 9
    {-1, -1, -1, -1},    // a
    {-1, -1, 1, 0xc},    // b
    {0xd, 0xe, 0xb, -1}, // c
    {-1, 0xc, -1, -1},   // d
    {0xc, 0xf, -1, -1},  // e
    {0xe, -1, -1, -1},   // f
};

#endif

int main(void) {
  while (1) {
    printf("you are in room %x\n", room);
    enum dir d = getcmd();
#ifdef FUNCS
    int old_room = room;
    switch (room) {
    case 0:
      room0(d);
      break;
    case 1:
      room1(d);
      break;
    case 2:
      room2(d);
      break;
    case 3:
      room3(d);
      break;
    case 4:
      room4(d);
      break;
    case 5:
      room5(d);
      break;
    case 6:
      room6(d);
      break;
    case 7:
      room7(d);
      break;
    case 8:
      room8(d);
      break;
    case 9:
      room9(d);
      break;
    case 0xb:
      roomb(d);
      break;
    case 0xc:
      roomc(d);
      break;
    case 0xd:
      roomd(d);
      break;
    case 0xe:
      roome(d);
      break;
    case 0xf:
      roomf(d);
      break;
    default:
      assert(0);
    }
    if (room == old_room)
      printf("sorry, can't go that way\n");
#else
    int next = map[room][d];
    if (next == -1)
      printf("sorry, can't go that way\n");
    else
      room = next;
#endif
    assert(room >= 0 && room <= 0xf);
    if (room == 0xa)
      win();
  }
  return 0;
}