Unique Paths II

 

    int uniquePathsWithObstacles(vector<vector<int> > &obstacleGrid) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        if(obstacleGrid[0][0]==1)
            return 0;
        int m = obstacleGrid.size();
        int n = obstacleGrid[0].size();
        vector<vector<int>> dp(m,vector<int>(n,0));
        int i,j;
        dp[0][0] = 1;
        for(j=1;j<n;j++)
            dp[0][j] = (obstacleGrid[0][j]?0:dp[0][j-1]);
        for(i=1;i<m;i++)
            dp[i][0] = (obstacleGrid[i][0]?0:dp[i-1][0]);
            
        for(i=1;i<m;i++)
            for(j=1;j<n;j++)
                dp[i][j] = (obstacleGrid[i][j]?0:dp[i-1][j]+dp[i][j-1]);
        return dp[m-1][n-1];
        
    }