999.cpp

class Solution { // 0ms
public:
  int numRookCaptures(vector<vector<char>> &b) {
    const vector<pair<int, int>> dir = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
    int ret = 0;
    for (auto i = 0; i < b.size(); ++i)
      for (auto j = 0; j < b[i].size(); ++j)
        if (b[i][j] == 'R') {
          for (const auto [dx, dy] : dir) {
            int x = i, y = j;
            while (x >= 0 && x < b.size() && y >= 0 && y < b[x].size() &&
                   b[x][y] != 'B') {
              if (b[x][y] == 'p') {
                ++ret;
                break;
              }
              x += dx;
              y += dy;
            }
          }
          break;
        }
    return ret;
  }
};