Problem p00632 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <list>
#include <set>
#include <stdio.h>
#include <string.h>

using namespace std;

// #define DEBUG

typedef struct {
  int px, py;
  int gx, gy;
  int move_index;
  int depth;
} DATA;

char map[20 + 2][20 + 2];
char move_inst[11];
set<unsigned> lstHash;
list<DATA> lstSarch;

unsigned calc_hash(const DATA &data) {
  unsigned hash;

  hash = data.px | (data.py << 5) | (data.gx << 10) | (data.gy << 15) |
         (data.move_index << 20);

  return (hash);
}

bool is_add(const DATA &data) {
  unsigned hash;

  hash = calc_hash(data);
  if (map[data.px][data.py] == -1 || map[data.px][data.py] == '#' ||
      lstHash.find(hash) != lstHash.end()) {
    return (false);
  }

  return (true);
}

int width_priority_sarch(const DATA &data) {
  DATA add;

  add.depth = data.depth + 1;
  add.move_index = (data.move_index + 1) % strlen(move_inst);

  add.gx = data.gx;
  add.gy = data.gy;
  switch (move_inst[data.move_index]) {
  case '8':
    add.gy--;
    break;
  case '4':
    add.gx--;
    break;
  case '6':
    add.gx++;
    break;
  case '2':
    add.gy++;
    break;
  default:
    break;
  }

  if (map[add.gx][add.gy] == -1) {
    add.gx = data.gx;
    add.gy = data.gy;
  }

  add.px = data.px;
  add.py = data.py;
  if (is_add(add) == true) {
    lstSarch.push_back(add);
    lstHash.insert(calc_hash(add));
  }
#ifdef DEBUG
  printf("%d %d\\n", add.move_index, data.move_index);
  printf("%u %u\\n", calc_hash(add), calc_hash(data));
#endif

  add.px++;
  if (is_add(add) == true) {
    lstSarch.push_back(add);
    lstHash.insert(calc_hash(add));
  }
  add.px = data.px;
  add.px--;
  if (is_add(add) == true) {
    lstSarch.push_back(add);
    lstHash.insert(calc_hash(add));
  }
  add.px = data.px;
  add.py++;
  if (is_add(add) == true) {
    lstSarch.push_back(add);
    lstHash.insert(calc_hash(add));
  }
  add.py = data.py;
  add.py--;
  if (is_add(add) == true) {
    lstSarch.push_back(add);
    lstHash.insert(calc_hash(add));
  }

  return (0);
}

bool is_end(DATA &data) {
  if (data.px == data.gx && data.py == data.gy) {
    return (true);
  }
  return (false);
}

int main(void) {
  DATA start;
  int hight, with;

  while (1) {
    lstHash.clear();
    lstSarch.clear();

    scanf("%d%d", &hight, &with);

    if (hight == 0 || with == 0) {
      break;
    }

    for (int i = 0; i < 22; i++) {
      for (int j = 0; j < 22; j++) {
        map[i][j] = -1;
      }
    }
    for (int y = 0; y < hight; y++) {
      char str[21];
      scanf("%s", str);
      for (int x = 0; x < with; x++) {
        map[x + 1][y + 1] = str[x];
        if (map[x + 1][y + 1] == 'A') {
          start.px = x + 1;
          start.py = y + 1;
          map[x + 1][y + 1] = '.';
        }
        if (map[x + 1][y + 1] == 'B') {
          start.gx = x + 1;
          start.gy = y + 1;
          map[x + 1][y + 1] = '.';
        }
      }
    }
    scanf("%s", move_inst);
    start.move_index = 0;
    start.depth = 0;

    lstHash.insert(calc_hash(start));
    lstSarch.push_back(start);

    while (lstSarch.empty() == false && is_end(lstSarch.front()) == false) {
#ifdef DEBUG
      printf("%d %d %d %d %d %d\\n", lstSarch.front().px, lstSarch.front().py,
             lstSarch.front().gx, lstSarch.front().gy, lstSarch.front().depth,
             lstSarch.front().move_index);
#endif
      width_priority_sarch(lstSarch.front());
      lstSarch.pop_front();
    }

    if (lstSarch.empty() == true) {
      puts("impossible");
    } else {
      printf("%d %d %d\\n", lstSarch.front().depth, lstSarch.front().py - 1,
             lstSarch.front().px - 1);
    }
  }

  return (0);
}

Error: TLE

Fixed submission:

#include <algorithm>
#include <list>
#include <stdio.h>
#include <string.h>

using namespace std;

// #define DEBUG

typedef struct {
  int px, py;
  int gx, gy;
  int move_index;
  int depth;
} DATA;

char map[20 + 2][20 + 2];
char move_inst[11];
list<unsigned> lstHash;
list<DATA> lstSarch;

unsigned calc_hash(const DATA &data) {
  unsigned hash;

  hash = data.px | (data.py << 5) | (data.gx << 10) | (data.gy << 15) |
         (data.move_index << 20);

  return (hash);
}

bool is_add(const DATA &data) {
  unsigned hash;

  hash = calc_hash(data);
  if (map[data.px][data.py] == -1 || map[data.px][data.py] == '#' ||
      find(lstHash.begin(), lstHash.end(), hash) != lstHash.end()) {
    return (false);
  }

  return (true);
}

int width_priority_sarch(const DATA &data) {
  DATA add;

  add.depth = data.depth + 1;
  add.move_index = (data.move_index + 1) % strlen(move_inst);

  add.gx = data.gx;
  add.gy = data.gy;
  switch (move_inst[data.move_index]) {
  case '8':
    add.gy--;
    break;
  case '4':
    add.gx--;
    break;
  case '6':
    add.gx++;
    break;
  case '2':
    add.gy++;
    break;
  default:
    break;
  }

  if (map[add.gx][add.gy] == -1) {
    add.gx = data.gx;
    add.gy = data.gy;
  }

  add.px = data.px;
  add.py = data.py;
  if (is_add(add) == true) {
    lstSarch.push_back(add);
    lstHash.push_back(calc_hash(add));
  }
#ifdef DEBUG
  printf("%d %d\\n", add.move_index, data.move_index);
  printf("%u %u\\n", calc_hash(add), calc_hash(data));
#endif

  add.px++;
  if (is_add(add) == true) {
    lstSarch.push_back(add);
    lstHash.push_back(calc_hash(add));
  }
  add.px = data.px;
  add.px--;
  if (is_add(add) == true) {
    lstSarch.push_back(add);
    lstHash.push_back(calc_hash(add));
  }
  add.px = data.px;
  add.py++;
  if (is_add(add) == true) {
    lstSarch.push_back(add);
    lstHash.push_back(calc_hash(add));
  }
  add.py = data.py;
  add.py--;
  if (is_add(add) == true) {
    lstSarch.push_back(add);
    lstHash.push_back(calc_hash(add));
  }

  return (0);
}

bool is_end(DATA &data) {
  if (data.px == data.gx && data.py == data.gy) {
    return (true);
  }
  return (false);
}

int main(void) {
  DATA start;
  int hight, with;

  while (1) {
    lstHash.clear();
    lstSarch.clear();

    scanf("%d%d", &hight, &with);

    if (hight == 0 || with == 0) {
      break;
    }

    for (int i = 0; i < 22; i++) {
      for (int j = 0; j < 22; j++) {
        map[i][j] = -1;
      }
    }
    for (int y = 0; y < hight; y++) {
      char str[21];
      scanf("%s", str);
      for (int x = 0; x < with; x++) {
        map[x + 1][y + 1] = str[x];
        if (map[x + 1][y + 1] == 'A') {
          start.px = x + 1;
          start.py = y + 1;
          map[x + 1][y + 1] = '.';
        }
        if (map[x + 1][y + 1] == 'B') {
          start.gx = x + 1;
          start.gy = y + 1;
          map[x + 1][y + 1] = '.';
        }
      }
    }
    scanf("%s", move_inst);
    start.move_index = 0;
    start.depth = 0;

    lstHash.push_back(calc_hash(start));
    lstSarch.push_back(start);

    while (lstSarch.empty() == false && is_end(lstSarch.front()) == false) {
#ifdef DEBUG
      printf("%d %d %d %d %d %d\\n", lstSarch.front().px, lstSarch.front().py,
             lstSarch.front().gx, lstSarch.front().gy, lstSarch.front().depth,
             lstSarch.front().move_index);
#endif
      width_priority_sarch(lstSarch.front());
      lstSarch.pop_front();
    }

    if (lstSarch.empty() == true) {
      puts("impossible");
    } else {
      printf("%d %d %d\\n", lstSarch.front().depth, lstSarch.front().py - 1,
             lstSarch.front().px - 1);
    }
  }

  return (0);
}