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Robot Room Cleaner

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Description

https://leetcode.com/problems/robot-room-cleaner/description/

Solution

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/**
 * // This is the robot's control interface.
 * // You should not implement it, or speculate about its implementation
 * class Robot {
 *   public:
 *     // Returns true if the cell in front is open and robot moves into the cell.
 *     // Returns false if the cell in front is blocked and robot stays in the current cell.
 *     bool move();
 *
 *     // Robot will stay in the same cell after calling turnLeft/turnRight.
 *     // Each turn will be 90 degrees.
 *     void turnLeft();
 *     void turnRight();
 *
 *     // Clean the current cell.
 *     void clean();
 * };
 */
class Solution {
public:
    void cleanRoom(Robot& robot) {
        int x = 0;
        int y = 0;    
        unordered_map<int, unordered_map<int, bool>> visited;
        int direction = 0;
        cleanHelper(robot, visited, x, y, direction);
        return;
    }
    
    void cleanHelper(Robot& robot, unordered_map<int, unordered_map<int, bool>>& visited, int x, int y, int direction) {
        if (visited[x][y] == true) return;
        vector<vector<int>> directions = {{-1, 0}, {0, 1}, {1, 0}, {0, -1}};
        visited[x][y] = true;
        robot.clean();
        for (int i = 0; i < 4; ++i) {
            if (robot.move()) {
                cleanHelper(robot, visited, x + directions[direction][0], y + directions[direction][1], direction);
                robot.turnLeft();
                robot.turnLeft();
                robot.move();
                robot.turnLeft();
                robot.turnLeft();
            }
            robot.turnLeft();
            direction = (direction + 1) % 4;
        }
        return;
    }
    
};