leetcode

0 struct Hash {

1 size_t operator()(const tuple<int, int> &t) const { return (get<0>(t) << 16) + get<1>(t); }

2 };

3

4 class Solution {

5 public:

6 bool isPathCrossing(const string &path) const {

7 static const pair<int, int> moves[128] = {

8 ['N'] = {-1, 0}, ['S'] = {1, 0}, ['E'] = {0, 1}, ['W'] = {0, -1}};

9 unordered_set<tuple<int, int>, Hash> us;

10 int x = 0, y = 0;

11 us.insert({0, 0});

12 for (const char c : path) {

13 x += moves[c].first;

14 y += moves[c].second;

15 if (us.count({x, y})) return true;

16 us.insert({x, y});

17 }

18 return false;

19 }

20 };