Package g1001_1100.s1041_robot_bounded_in_circle

Class Solution

java.lang.Object
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 `(0, 0)` and faces north. Note that: * The **north direction** is the positive direction of the y-axis. * The **south direction** is the negative direction of the y-axis. * The **east direction** is the positive direction of the x-axis. * The **west direction** is the negative direction of the x-axis. The robot can receive one of three instructions: * `"G"`: go straight 1 unit. * `"L"`: turn 90 degrees to the left (i.e., anti-clockwise direction). * `"R"`: turn 90 degrees to the right (i.e., clockwise direction). The robot performs the `instructions` given in order, and repeats them forever. Return `true` 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:** * `1 <= instructions.length <= 100` * `instructions[i]` is `'G'`, `'L'` or, `'R'`.

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • isRobotBounded

      public boolean isRobotBounded(String instructions)