Create robot-bounded-in-circle.py

Author: kamyu104

Python/robot-bounded-in-circle.py

@@ -0,0 +1,20 @@
+# Time:  O(n)
+# Space: O(1)
+
+class Solution(object):
+    def isRobotBounded(self, instructions):
+        """
+        :type instructions: str
+        :rtype: bool
+        """
+        directions = [[ 1, 0], [0, -1], [-1, 0], [0, 1]]
+        x, y, i = 0, 0, 0
+        for instruction in instructions:
+            if instruction == 'R':
+                i = (i+1) % 4;
+            elif instruction == 'L':
+                i = (i-1) % 4;
+            else:
+                x += directions[i][0]
+                y += directions[i][1]
+        return (x == 0 and y == 0) or i > 0