This is my CPP solution.
class Solution {
public:
int uniquePathsWithObstacles(vector<vector<int>>&grid) {
int m = grid.size(), n = grid[0].size();
long long int a[m][n];
for(int i=0;i<m;i++)
for(int j=0;j<n;j++)
a[i][j] = grid[i][j];
if(a[0][0] == 1){
return 0;
}else{
a[0][0] = 1;
}
for(int j=1;j<n;j++){
if(a[0][j] == 0)
a[0][j] = a[0][j-1];
else
a[0][j] = 0;
}
for(int i=1;i<m;i++){
if(a[i][0] == 0)
a[i][0] = a[i-1][0];
else
a[i][0] = 0;
}
for(int i=1;i<m;i++){
for(int j=1;j<n;j++){
if(a[i][j] == 0){
a[i][j] = a[i][j-1] + a[i-1][j];
}
else{
a[i][j] = 0;
}
}
}
return a[m-1][n-1];
}
};