leetcode-go/bailian/4130.saving-tang-monk/main.cc

#include <cstdio>
#include <cstring>
#include <queue>

using namespace std;

const int N = 100;
const int M = 9;
const int S = 5;

const char dx[4] = {1, 0, -1, 0};
const char dy[4] = {0, 1, 0, -1};

char map[N][N + 1];
char snake[N][N];
bool flag[N][N][M + 1][1 << S];

struct Pos {
  char r;
  char c;
  char key;
  bool kill;
  char died;
  int t;
  Pos(char r = 0, char c = 0, char key = 0, bool kill = false, char died = 0,
      int t = 0)
      : r(r), c(c), key(key), kill(kill), died(died), t(t) {}
  bool operator==(const Pos &that) const {
    return this->r == that.r && this->c == that.c && this->key == that.key;
  }
};

char n, m;

bool is_expandable(char x, char y, char key, char died) {
  if (x < 0 || n <= x || y < 0 || n <= y) return false;
  if (map[x][y] == '#' || flag[x][y][key][died]) return false;
  return true;
}

int main() {
  while (scanf("%d %d", &n, &m) != EOF) {
    if (n == 0 && m == 0) break;
    Pos sun, tang;
    int s = 0;
    for (char i = 0; i < n; i++) {
      scanf("%s", map[i]);
      for (char j = 0; j < n; j++) {
        if (map[i][j] == 'T') {
          tang.r = i;
          tang.c = j;
          tang.key = m;
          tang.t = -1;
        } else if (map[i][j] == 'K') {
          sun.r = i;
          sun.c = j;
        } else if (map[i][j] == 'S') {
          snake[i][j] = s++;
        }
      }
    }
    queue<Pos> q;
    q.push(sun);
    memset(flag, 0, sizeof(flag));
    flag[sun.r][sun.c][0][0] = true;
    while (!q.empty()) {
      Pos &cur = q.front();
      q.pop();
      if (cur == tang) {
        tang.t = cur.t;
        break;
      }
      for (int i = 0; i < 4; i++) {
        int nx = cur.r + dx[i];
        int ny = cur.c + dy[i];
      }
    }
    if (tang.t == -1)
      printf("impossible\n");
    else
      printf("%d\n", tang.t);
  }
  return 0;
}