class Solution {
public:
    int uniquePathsWithObstacles(vector<vector<int>>& obstacleGrid) {
        int m = obstacleGrid.size();
        int n = obstacleGrid[0].size();

        int dp[m][n];

        memset(dp, 0, sizeof(dp));

        for(int i = 0; i < m && obstacleGrid[i][0] == 0; i++) dp[i][0] = 1;
        for(int j = 0; j < n && obstacleGrid[0][j] == 0; j++) dp[0][j] = 1;

        for(int i = 1; i < m; i++) {
            for(int j = 1; j < n; j++) {
                if(obstacleGrid[i][j] != 1) {
                    dp[i][j] = dp[i-1][j] + dp[i][j-1];
                } 
            }
        }

        return dp[m-1][n-1];
    }
};