LeetCode(Permutations)

class Solution {
public:
vector<vector<int> > permute(vector<int>& num) {
sort(num.begin(),num.end());
vector<vector<int> > result;
vector<int> path;
dfs(num,result,path);
return result;
}
void dfs(vector<int> &num,vector<vector<int> > &result,vector<int> &path)
{
if(path.size()==num.size())
{
result.push_back(path);
return;
}
for(int i=0;i<num.size();++i)
{
if(find(path.begin(),path.end(),num[i])==path.end())
{
path.push_back(num[i]);
dfs(num,result,path);
path.pop_back();
}
}
}
};

class Solution {
public:
vector<vector<int> > permuteUnique(vector<int>& num) {
sort(num.begin(),num.end());
vector<vector<int>> result;
vector<int> path;
unordered_map<int,int> map;
for(int i=0;i<num.size();++i)
{
if(map.find(num[i])==map.end())map[num[i]]=1;
else ++map[num[i]];
}
dfs(num,result,path,map);
return result;
}
void dfs(vector<int> &num,vector<vector<int> > &result,vector<int> &path,unordered_map<int,int> &map)
{
if(path.size()==num.size())result.push_back(path);
for(unordered_map<int,int>::iterator i=map.begin();i!=map.end();++i)
{
int cnt=0;
for(int j=0;j<path.size();++j)
{
if(path[j]==i->first)++cnt;
}
if(cnt<i->second)
{
path.push_back(i->first);
dfs(num,result,path,map);
path.pop_back();
}
}
}
};