Solution.java

import java.util.Arrays;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;
import java.util.Set;

public class Solution {

    private static final Scanner scanner = new Scanner(System.in);

	public static void main(String[] args) {
        int obstaclesCount = scanner.nextInt();
        int commandsCount = scanner.nextInt();
        
        scanner.nextLine();
        
        //collect obstacles
        List<int[]> obstacles = new LinkedList<>();
        for(int i = 0; i < obstaclesCount; i++) {
        	String[] ob = scanner.nextLine().split(" ");
        	int x = Integer.parseInt(ob[0]);
        	int y = Integer.parseInt(ob[1]);
        	obstacles.add(new int[] {x, y});
        }
        
        //collect commands
        List<Command> commands = new LinkedList<>();
        String commandLine;
        for(int i = 0; i < commandsCount; i++) {
            commandLine = scanner.nextLine();
            //Moves
            if(commandLine.length() > 1) {
            	String moveVal = commandLine.substring(2);
            	commands.add(new Move(Integer.parseInt(moveVal)));
            }
            //Rotations
            else{
            	if(commandLine.charAt(0) == 'L') {
            		commands.add(new Rotate(0));
            	}else {
            		commands.add(new Rotate(1));
            	}
            }
        }
        
        Robot robot = new Robot();
        float result = processCommands(robot, commands, obstacles);
        
	}

	
	public static float processCommands(Robot robot, List<Command> commands, List<int[]> obstacles) {
		float maxEuclideanDistance = 0;
		//robot at (0,0), pointing North
		for(Command c: commands) {
			
			//update direction
			if(c instanceof Rotate) {
				if(((Rotate) c).direction == 0) {	//turn left
					int newDirection = (robot.getDirection() - 1 + 4) % 4;
					robot.setDirection(newDirection);
				}
				if(((Rotate) c).direction == 1) {	//turn right
					int newDirection = robot.getDirection() + 1 % 4;
					robot.setDirection(newDirection);
				}
			}
			
			//update location after move
			else if(c instanceof Move) {
				int dir = robot.getDirection();
				int projectedX, projectedY;
				boolean metObstacle = false;
				int finalX = robot.getCurrentX();
				int finalY = robot.getCurrentY();
				
				//calculate PROJECTED location and FINAL location after move
				if(dir == 0) {	//North
					projectedX = robot.getCurrentX();
					projectedY = robot.getCurrentY() + ((Move) c).getDistance();
					
					for(int i = robot.getCurrentY(); i < projectedY; i++) {
						int[] coord = new int[] {robot.getCurrentX(), i};
						for(int[] obstacle: obstacles) {
							if(Arrays.equals(obstacle, coord)) {
								metObstacle = true;
							}
						}
						if(metObstacle) {
							finalX = robot.getCurrentX();
							finalY = i - 1;
							break;
						}
					}
				}else if (dir == 1) {	//East
					projectedX = robot.getCurrentX() + ((Move) c).getDistance();
					projectedY = robot.getCurrentY();
					
					for(int i = robot.getCurrentX(); i < projectedX; i++) {
						int[] coord = new int[] {i, robot.getCurrentY()};
						for(int[] obstacle: obstacles) {
							if(Arrays.equals(obstacle, coord)) {
								metObstacle = true;
							}
						}
						if(metObstacle) {
							finalX = i - 1;
							finalY = robot.getCurrentY();
							break;
						}
					}
					
				}else if (dir == 2) {	//South
					projectedX = robot.getCurrentX();
					projectedY = robot.getCurrentY() - ((Move) c).getDistance();
					
					for(int i = robot.getCurrentY(); i > projectedY; i--) {
						int[] coord = new int[] {robot.getCurrentX(), i};
						for(int[] obstacle: obstacles) {
							if(Arrays.equals(obstacle, coord)) {
								metObstacle = true;
							}
						}
						if(metObstacle) {
							finalX = robot.getCurrentX();
							finalY = i + 1;
							break;
						}
					}
					
				}else if (dir == 3) {	//West
					projectedX = robot.getCurrentX() - ((Move) c).getDistance();
					projectedY = robot.getCurrentY();
					
					//check if obstacle encountered
					for(int i = robot.getCurrentX(); i > projectedX; i--) {
						int[] coord = new int[] {i, robot.getCurrentY()};
						for(int[] obstacle: obstacles) {
							if(Arrays.equals(obstacle, coord)) {
								metObstacle = true;
							}
						}
						if(metObstacle) {
							finalX = i + 1;
							finalY = robot.getCurrentY();
							break;
						}
					}
				}
				
				//calculate real location
				System.out.println(finalX);
				System.out.println(finalY);
				System.out.println("finalX : " + finalX + " finalY: " + finalY);
				
				//set robot's real location
				robot.setLocation(finalX, finalY);
				
			}
			
			//compute distance from origin after move
			float currentDistance = 0;
			//update maxEuclideanDistance
			maxEuclideanDistance = Math.max(currentDistance, maxEuclideanDistance);
		}
		return maxEuclideanDistance;
	}
}

class Robot {
	int currentX;
	int currentY;
	
	int direction = 0; //0 = North, 1 = East, 2 = South, 3 = West
	public Robot() {
		
	}
	
	public int getCurrentX() {
		return this.currentX;
	}
	
	public int getCurrentY() {
		return this.currentY;
	}
	
	public void setLocation(int x, int y) {
		this.currentX = x;
		this.currentY = y;
	}
	
	public int getDirection() {
		return this.direction;
	}
	
	public void setDirection(int direction) {
		this.direction = direction;
	}
}

class Command {
	
}

class Move extends Command {
	int distance;
	public Move(int distance) {
		this.distance = distance;
	}
	
	public int getDistance() {
		return this.distance;
	}
}

class Rotate extends Command {
	int direction;	//0 = Left, 1 = Right
	public Rotate(int direction) {
		this.direction = direction;
	}
}