<p>Given a collection of candidate numbers (<code>candidates</code>) and a target number (<code>target</code>), find all unique combinations in <code>candidates</code>&nbsp;where the candidate numbers sum to <code>target</code>.</p>

<p>Each number in <code>candidates</code>&nbsp;may only be used <strong>once</strong> in the combination.</p>

<p><strong>Note:</strong>&nbsp;The solution set must not contain duplicate combinations.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> candidates = [10,1,2,7,6,1,5], target = 8
<strong>Output:</strong> 
[
[1,1,6],
[1,2,5],
[1,7],
[2,6]
]
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> candidates = [2,5,2,1,2], target = 5
<strong>Output:</strong> 
[
[1,2,2],
[5]
]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;=&nbsp;candidates.length &lt;= 100</code></li>
	<li><code>1 &lt;=&nbsp;candidates[i] &lt;= 50</code></li>
	<li><code>1 &lt;= target &lt;= 30</code></li>
</ul>

class Solution {
public:

    void solve(int ind, vector<int> &ds,vector<int>& candidates,int sum, int target
                ,vector<vector<int>>&ans )
        {
            if(sum==target)
            {
                ans.push_back(ds);
                return;
            }
            if(sum>target) return;
            if(ind==candidates.size()) return;
            
            

            unordered_map<int,int>mpp;
            for(int i=ind;i<candidates.size();i++)
            {
                if(mpp.find(candidates[i])==mpp.end())
                {
                    mpp[candidates[i]]++;
                    ds.push_back(candidates[i]);
                    solve(i+1,ds,candidates,sum+candidates[i],target,ans);
                    ds.pop_back();
                }
            }




        }








    vector<vector<int>> combinationSum2(vector<int>& candidates, int target) {
        sort(candidates.begin(),candidates.end());
        vector<int>ds;
        vector<vector<int>> ans;
        solve(0,ds,candidates,0,target,ans);
        return ans;
    }
};
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