leetcode

0 class Solution {

1 public:

2 int equalPairs(vector<vector<int>> &grid) {

3 int n = grid.size(), res = 0;

4 map<vector<int>, int> m;

5 for (const auto &vec : grid)

6 m[vec]++;

7

8 for (int i = 0; i < n; i++)

9 for (int j = 0; j < n; j++)

10 if (i < j) swap(grid[i][j], grid[j][i]);

11

12 for (const auto &vec : grid)

13 res += m[vec];

14 return res;

15 }

16 };