leetcode

0 class DetectSquares {

1 using point_t = tuple<int, int>;

2

3 unordered_map<int, unordered_set<int>> ys;

4 static int cnt[1001][1001];

5

6 public:

7 DetectSquares() { memset(cnt, 0x00, sizeof(cnt)); }

8

9 void add(const vector<int> &point) {

10 const int x = point[0];

11 const int y = point[1];

12

13 cnt[x][y]++;

14 ys[x].insert(y);

15 }

16

17 int count(const vector<int> &point) {

18 const int x = point[0];

19 const int y = point[1];

20 int res = 0;

21

22 for (const auto yp : ys[point[0]]) {

23 const int len = abs(y - yp);

24 if (!len) continue;

25 if (x + len <= 1000) res += cnt[x][yp] * cnt[x + len][y] * cnt[x + len][yp];

26 if (x >= len) res += cnt[x][yp] * cnt[x - len][y] * cnt[x - len][yp];

27 }

28

29 return res;

30 }

31 };

32

33 int DetectSquares::cnt[1001][1001];