<p>A robot on an infinite XY-plane starts at point <code>(0, 0)</code> facing north. The robot receives an array of integers <code>commands</code>, which represents a sequence of moves that it needs to execute. There are only three possible types of instructions the robot can receive:</p>

<ul>
	<li><code>-2</code>: Turn left <code>90</code> degrees.</li>
	<li><code>-1</code>: Turn right <code>90</code> degrees.</li>
	<li><code>1 &lt;= k &lt;= 9</code>: Move forward <code>k</code> units, one unit at a time.</li>
</ul>

<p>Some of the grid squares are <code>obstacles</code>. The <code>i<sup>th</sup></code> obstacle is at grid point <code>obstacles[i] = (x<sub>i</sub>, y<sub>i</sub>)</code>. If the robot runs into an obstacle, it will stay in its current location (on the block adjacent to the obstacle) and move onto the next command.</p>

<p>Return the <strong>maximum squared Euclidean distance</strong> that the robot reaches at any point in its path (i.e. if the distance is <code>5</code>, return <code>25</code>).</p>

<p><strong>Note:</strong></p>

<ul>
	<li>There can be an obstacle at <code>(0, 0)</code>. If this happens, the robot will ignore the obstacle until it has moved off the origin. However, it will be unable to return to <code>(0, 0)</code> due to the obstacle.</li>
	<li>North means +Y direction.</li>
	<li>East means +X direction.</li>
	<li>South means -Y direction.</li>
	<li>West means -X direction.</li>
</ul>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">commands = [4,-1,3], obstacles = []</span></p>

<p><strong>Output:</strong> <span class="example-io">25</span></p>

<p><strong>Explanation: </strong></p>

<p>The robot starts at <code>(0, 0)</code>:</p>

<ol>
	<li>Move north 4 units to <code>(0, 4)</code>.</li>
	<li>Turn right.</li>
	<li>Move east 3 units to <code>(3, 4)</code>.</li>
</ol>

<p>The furthest point the robot ever gets from the origin is <code>(3, 4)</code>, which squared is <code>3<sup>2</sup> + 4<sup>2 </sup>= 25</code> units away.</p>
</div>

<p><strong class="example">Example 2:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">commands = [4,-1,4,-2,4], obstacles = [[2,4]]</span></p>

<p><strong>Output:</strong> <span class="example-io">65</span></p>

<p><strong>Explanation:</strong></p>

<p>The robot starts at <code>(0, 0)</code>:</p>

<ol>
	<li>Move north 4 units to <code>(0, 4)</code>.</li>
	<li>Turn right.</li>
	<li>Move east 1 unit and get blocked by the obstacle at <code>(2, 4)</code>, robot is at <code>(1, 4)</code>.</li>
	<li>Turn left.</li>
	<li>Move north 4 units to <code>(1, 8)</code>.</li>
</ol>

<p>The furthest point the robot ever gets from the origin is <code>(1, 8)</code>, which squared is <code>1<sup>2</sup> + 8<sup>2</sup> = 65</code> units away.</p>
</div>

<p><strong class="example">Example 3:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">commands = [6,-1,-1,6], obstacles = [[0,0]]</span></p>

<p><strong>Output:</strong> <span class="example-io">36</span></p>

<p><strong>Explanation:</strong></p>

<p>The robot starts at <code>(0, 0)</code>:</p>

<ol>
	<li>Move north 6 units to <code>(0, 6)</code>.</li>
	<li>Turn right.</li>
	<li>Turn right.</li>
	<li>Move south 5 units and get blocked by the obstacle at <code>(0,0)</code>, robot is at <code>(0, 1)</code>.</li>
</ol>

<p>The furthest point the robot ever gets from the origin is <code>(0, 6)</code>, which squared is <code>6<sup>2</sup> = 36</code> units away.</p>
</div>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= commands.length &lt;= 10<sup>4</sup></code></li>
	<li><code>commands[i]</code> is either <code>-2</code>, <code>-1</code>, or an integer in the range <code>[1, 9]</code>.</li>
	<li><code>0 &lt;= obstacles.length &lt;= 10<sup>4</sup></code></li>
	<li><code>-3 * 10<sup>4</sup> &lt;= x<sub>i</sub>, y<sub>i</sub> &lt;= 3 * 10<sup>4</sup></code></li>
	<li>The answer is guaranteed to be less than <code>2<sup>31</sup></code>.</li>
</ul>

#include <unordered_set>
#include <vector>
#include <iostream>

class Solution {
public:
    int robotSim(std::vector<int>& commands, std::vector<std::vector<int>>& obstacles) {

        int max_distance = 0;
        int distance = 0;

        bool state = 1;     // 0 for x-axis and 1 for y-axis
        bool direction = 0; // 0 for +ve and 1 for -ve

        std::vector<std::vector<int>> coords;

        int x = 0, y = 0;

        // Create a set of obstacle points for quick lookup
        std::unordered_set<std::string> obstacleSet;
        for (const auto& obs : obstacles) {
            obstacleSet.insert(std::to_string(obs[0]) + "," + std::to_string(obs[1]));
        }

        for (int i = 0; i < commands.size(); i++) {

            if (commands[i] == -1) {

                if (state == 0 && direction == 0) {
                    state = 1;
                    direction = 1;
                } else if (state == 1 && direction == 0) {
                    state = 0;
                    direction = 0;
                } else if (state == 0 && direction == 1) {
                    state = 1;
                    direction = 0;
                } else if (state == 1 && direction == 1) {
                    state = 0;
                    direction = 1;
                }

            } else if (commands[i] == -2) {

                if (state == 0 && direction == 0) {
                    state = 1;
                    direction = 0;
                } else if (state == 1 && direction == 0) {
                    state = 0;
                    direction = 1;
                } else if (state == 0 && direction == 1) {
                    state = 1;
                    direction = 1;
                } else if (state == 1 && direction == 1) {
                    state = 0;
                    direction = 0;
                }

            } else {

                for (int step = 0; step < commands[i]; ++step) {
                    int newX = x, newY = y;

                    if (state == 0 && direction == 0) {
                        newX++;
                    } else if (state == 1 && direction == 0) {
                        newY++;
                    } else if (state == 0 && direction == 1) {
                        newX--;
                    } else if (state == 1 && direction == 1) {
                        newY--;
                    }

                    // Check if the next position is an obstacle
                    std::string newPos = std::to_string(newX) + "," + std::to_string(newY);
                    if (obstacleSet.find(newPos) != obstacleSet.end()) {
                        break; // Stop moving in this direction if obstacle encountered
                    }

                    // Update position
                    x = newX;
                    y = newY;
                    coords.push_back({x, y});
                }
            }
        }

        for (int i = 0; i < coords.size(); i++) {
            std::cout << coords[i][0] << ", " << coords[i][1] << std::endl;

            distance = (coords[i][0] * coords[i][0]) + (coords[i][1] * coords[i][1]);
            max_distance = std::max(distance, max_distance);
        }

        return max_distance;
    }
};

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