unique paths ii

int (vector<vector<int>>& obstacleGrid) {  
    int m = obstacleGrid.size();  
    int n = obstacleGrid[0].size();  
      
    vector<vector<int> > result(m);  
    for (int i = 0; i < m; i++) {  
        result[i].resize(n, 0);  
    }  
      
    result[0][0] = obstacleGrid[0][0] == 1 ? 0 : 1;  
    if (result[0][0] == 0) {  
        return 0;  
    }  
    for (int i = 1; i < n; i++) {  
        result[0][i] = obstacleGrid[0][i] == 1 ? 0 : result[0][i - 1];  
    }  
    for (int i = 1; i < m; i++) {  
        result[i][0] = obstacleGrid[i][0] == 1 ? 0 : result[i-1][0];  
    }  
    for (int i = 1; i < m; i++) {  
        for (int j = 1; j < n; j++) {  
            result[i][j] = obstacleGrid[i][j] == 1 ? 0 : result[i][j - 1] + result[i - 1][j];  
        }  
    }  
    return result[m - 1][n - 1];  
}