1#include <vector>
2#include <unordered_set>
3using namespace std;
4
5struct pair_hash {
6    template <class T1, class T2>
7    size_t operator () (const pair<T1, T2>& pair) const {
8        return hash<T1>()(pair.first) ^ hash<T2>()(pair.second);
9    }
10};
11
12int robotSim(vector<int>& commands, vector<vector<int>>& obstacles) {
13    unordered_set<pair<int,int>, pair_hash> obstacle_set;
14    for (auto& obs : obstacles) {
15        obstacle_set.insert({obs[0], obs[1]});
16    }
17    vector<int> dx = {0, 1, 0, -1};
18    vector<int> dy = {1, 0, -1, 0};
19    int x = 0, y = 0, direction = 0, max_dist_sq = 0;
20
21    for (int cmd : commands) {
22        if (cmd == -2) { // Turn left
23            direction = (direction + 3) % 4;
24        } else if (cmd == -1) { // Turn right
25            direction = (direction + 1) % 4;
26        } else {
27            for (int k = 0; k < cmd; ++k) {
28                int nx = x + dx[direction];
29                int ny = y + dy[direction];
30                if (obstacle_set.find({nx, ny}) == obstacle_set.end()) {
31                    x = nx;
32                    y = ny;
33                    max_dist_sq = max(max_dist_sq, x * x + y * y);
34                } else {
35                    break;
36                }
37            }
38        }
39    }
40
41    return max_dist_sq;
42}