g1001_1100.s1041_robot_bounded_in_circle.Solution

public class Solution extends Object

1041 - Robot Bounded In Circle.Medium On an infinite plane, a robot initially stands at <code>(0, 0)</code> and faces north. Note that: <ul> <li>The north direction is the positive direction of the y-axis.</li> <li>The south direction is the negative direction of the y-axis.</li> <li>The east direction is the positive direction of the x-axis.</li> <li>The west direction is the negative direction of the x-axis.</li> </ul> The robot can receive one of three instructions: <ul> <li><code>"G"</code>: go straight 1 unit.</li> <li><code>"L"</code>: turn 90 degrees to the left (i.e., anti-clockwise direction).</li> <li><code>"R"</code>: turn 90 degrees to the right (i.e., clockwise direction).</li> </ul> The robot performs the <code>instructions</code> given in order, and repeats them forever. Return <code>true</code> if and only if there exists a circle in the plane such that the robot never leaves the circle. Example 1: Input: instructions = “GGLLGG” Output: true Explanation: The robot is initially at (0, 0) facing the north direction. “G”: move one step. Position: (0, 1). Direction: North. “G”: move one step. Position: (0, 2). Direction: North. “L”: turn 90 degrees anti-clockwise. Position: (0, 2). Direction: West. “L”: turn 90 degrees anti-clockwise. Position: (0, 2). Direction: South. “G”: move one step. Position: (0, 1). Direction: South. “G”: move one step. Position: (0, 0). Direction: South. Repeating the instructions, the robot goes into the cycle: (0, 0) –> (0, 1) –> (0, 2) –> (0, 1) –> (0, 0). Based on that, we return true. Example 2: Input: instructions = “GG” Output: false Explanation: The robot is initially at (0, 0) facing the north direction. “G”: move one step. Position: (0, 1). Direction: North. “G”: move one step. Position: (0, 2). Direction: North. Repeating the instructions, keeps advancing in the north direction and does not go into cycles. Based on that, we return false. Example 3: Input: instructions = “GL” Output: true Explanation: The robot is initially at (0, 0) facing the north direction. “G”: move one step. Position: (0, 1). Direction: North. “L”: turn 90 degrees anti-clockwise. Position: (0, 1). Direction: West. “G”: move one step. Position: (-1, 1). Direction: West. “L”: turn 90 degrees anti-clockwise. Position: (-1, 1). Direction: South. “G”: move one step. Position: (-1, 0). Direction: South. “L”: turn 90 degrees anti-clockwise. Position: (-1, 0). Direction: East. “G”: move one step. Position: (0, 0). Direction: East. “L”: turn 90 degrees anti-clockwise. Position: (0, 0). Direction: North. Repeating the instructions, the robot goes into the cycle: (0, 0) –> (0, 1) –> (-1, 1) –> (-1, 0) –> (0, 0). Based on that, we return true. Constraints: <ul> <li><code>1 <= instructions.length <= 100</code></li> <li><code>instructions[i]</code> is <code>'G'</code>, <code>'L'</code> or, <code>'R'</code>.</li> </ul>

Constructor Summary

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Constructor

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Solution()
Method Summary

Modifier and Type

Method

Description

boolean

isRobotBounded(String instructions)

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details
- Solution
  
  public Solution()
Method Details
- isRobotBounded
  
  public boolean isRobotBounded(String instructions)

Class Solution

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Methods inherited from class java.lang.Object

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Solution

Method Details

isRobotBounded