lec10_21.cpp

class Solution {
    public:
    int f (int i , int j , vector<vector<int>> &mat, vector<vector<int>>&dp){
        // if(i>=0 && j>=0 && mat[i][j] == -1) return 0 ;
         if (i >= 0 && j >= 0 && mat[i][j] == 1) return 0; 
        if( i == 0 && j == 0 ) return 1;
    
        if(i< 0 || j<0) return 0 ;
        if(dp[i][j]!=-1) return dp[i][j];
        int up = f(i - 1, j , mat ,dp);
        int left = f(i , j-1 , mat,dp);
        return dp[i][j]= up+ left;
    }
        int uniquePathsWithObstacles(vector<vector<int>>& obstacleGrid) {
            int n = obstacleGrid.size();
            int m = obstacleGrid[0].size();
            vector<vector<int>>dp( n , vector<int>(m , -1));
    
            return f(n-1 , m -1 , obstacleGrid , dp);
        }
    };