简单回朔题
class Solution {
public:
//start=0;
void func(int start,int k,int n,vector<int>& temp,vector<vector<int>>& result)
{
if(temp.size()==k)
result.push_back(temp);
else
{
for(int i=start+1;i<=n;i++)
{
temp.push_back(i);
func(i,k,n,temp,result);
temp.pop_back();
}
}
return;
}
vector<vector<int>> combine(int n, int k) {
int start=0;
vector<int> temp;
vector<vector<int>> result;
func(start,k,n,temp,result);
return result;
}
};