leetcode

0 class Solution {

1 public:

2 int uniquePaths(int n, int m) {

3 vector<vector<int>> mat(n, vector<int>(m, 0));

4 queue<pair<int, int>> q;

5 q.push({n - 1, m - 1}), mat[n - 1][m - 1] = 1;

6 while (!q.empty()) {

7 auto [x, y] = q.front();

8 q.pop();

9 if (x - 1 >= 0) {

10 mat[x - 1][y] += mat[x][y];

11 if (mat[x - 1][y] == mat[x][y]) q.push({x - 1, y});

12 }

13 if (y - 1 >= 0) {

14 mat[x][y - 1] += mat[x][y];

15 if (mat[x][y - 1] == mat[x][y]) q.push({x, y - 1});

16 }

17 }

18 return mat[0][0];

19 }

20 };