63.cpp

#include <iostream>
#include <vector>
#include <cassert>

using namespace std;

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

        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] == 0) {
                    dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
                }
            }
        }

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

int main()
{
    Solution s;
    vector<vector<int>> obstacleGrid = {{0,0,0},{0,1,0},{0,0,0}};
    int ret = s.uniquePathsWithObstacles(obstacleGrid);
    assert(ret == 2);
    return 0;
}