874 - Walking Robot Simulation

 JAVA

• class Solution {
      public int robotSim(int[] commands, int[][] obstacles) {
          int[] dirs = {0, 1, 0, -1, 0};
          Set<Integer> s = new HashSet<>(obstacles.length);
          for (var e : obstacles) {
              s.add(f(e[0], e[1]));
          }
          int ans = 0, k = 0;
          int x = 0, y = 0;
          for (int c : commands) {
              if (c == -2) {
                  k = (k + 3) % 4;
              } else if (c == -1) {
                  k = (k + 1) % 4;
              } else {
                  while (c-- > 0) {
                      int nx = x + dirs[k], ny = y + dirs[k + 1];
                      if (s.contains(f(nx, ny))) {
                          break;
                      }
                      x = nx;
                      y = ny;
                      ans = Math.max(ans, x * x + y * y);
                  }
              }
          }
          return ans;
      }
  
      private int f(int x, int y) {
          return x * 60010 + y;
      }
  }

C++

• class Solution {
  public:
      int robotSim(vector<int>& commands, vector<vector<int>>& obstacles) {
          int dirs[5] = {0, 1, 0, -1, 0};
          auto f = [](int x, int y) {
              return x * 60010 + y;
          };
          unordered_set<int> s;
          for (auto& e : obstacles) {
              s.insert(f(e[0], e[1]));
          }
          int ans = 0, k = 0;
          int x = 0, y = 0;
          for (int c : commands) {
              if (c == -2) {
                  k = (k + 3) % 4;
              } else if (c == -1) {
                  k = (k + 1) % 4;
              } else {
                  while (c--) {
                      int nx = x + dirs[k], ny = y + dirs[k + 1];
                      if (s.count(f(nx, ny))) {
                          break;
                      }
                      x = nx;
                      y = ny;
                      ans = max(ans, x * x + y * y);
                  }
              }
          }
          return ans;
      }
  };