message: Update number-of-distinct-islands.cpp
diff: @@ -17,9 +17,9 @@ public:
  }
  private:
  -
  bool dfs(const int i, const int j,
  vector<vector<int>> *grid, string *island) {
  +
  static const unordered_map<char, pair<int, int>>
  directions = { {'l', {-1, 0} }, {'r', { 1, 0} },
  {'u', { 0, 1} }, {'d', { 0, -1} }};
  