Create 874. Walking Robot Simulation (#575)

Author: Chayandas07

874. Walking Robot Simulation

@@ -0,0 +1,37 @@
+
+class Solution {
+public:
+    int robotSim(vector<int>& commands, vector<vector<int>>& obstacles) {
+       
+        unordered_set<string> obs;
+        for (auto& obstacle : obstacles) {
+            obs.insert(to_string(obstacle[0]) + "," + to_string(obstacle[1]));
+        }
+
+        int x = 0, y = 0, dx = 0, dy = 1;
+        int ans = 0;
+
+        for (int c : commands) {
+            if (c == -1) { 
+                int temp = dx;
+                dx = dy; dy = -temp;
+            } else if (c == -2) { 
+                int temp = dx;
+                dx = -dy; dy = temp;
+            } else {
+  
+                for (int i = 0; i < c; ++i) {
+                    int xx = x + dx;
+                    int yy = y + dy;
+
+                    if (obs.find(to_string(xx) + "," + to_string(yy)) != obs.end()) break; 
+                    x = xx;
+                    y = yy;
+                    ans = max(ans, x * x + y * y); 
+                }
+            }
+        }
+
+        return ans;
+    }
+};