here is my code:

```
class Solution {
private:
vector<vector<int>> result;
vector<int> path;
public:
void dfs(int curDeep, int maxDeep, int start , int n)
{
if(curDeep == maxDeep)
{
result.push_back(path);
return ;
}
for(int i = start; i <= n; i++)
{
path[curDeep] = i;
dfs(curDeep + 1, maxDeep, start + 1, n);
}
}
vector<vector<int> > combine(int n, int k) {
path.resize(k);
this->dfs(0, k, 1, n);
return result;
}
};
```

i do not know the reason why I get this error:Memory Limit Exceeded pls help~ thank you