SRM407 Div2 Easy

250

やるだけ

class SpiralWalking {
public:
  int totalPoints(vector <string> levelMap)
  {

    const int di[] = {0, 1, 0, -1};
    const int dj[] = {1, 0, -1, 0};

    int i = 0;
    int j = 0;
    int d = 0;

    int sum = 0;

    const int h = levelMap.size();
    const int w = levelMap[0].size();

    for (int loop = h * w; loop--; ) {
      sum += (levelMap[i][j] - '0');

      int tmp = d;
      if (loop == 0) break;
      while (true) {
        int ni = i + di[d];
        int nj = j + dj[d];
        if (ni < 0 || nj < 0) d = (d + 1) % 4;
        else if (h <= ni || w <= nj) d = (d + 1) % 4;
        else if (levelMap[ni][nj] == '@') d = (d + 1) % 4;
        break;
      }
      if (tmp != d) sum -= (levelMap[i][j] - '0');
      levelMap[i][j] = '@';
      i = i + di[d];
      j = j + dj[d];
    }

    return sum;
  }
};