<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:
    vector<vector<int>> res;
    int n;
    void ans(vector<int>& candidates, int target, vector<int> subset, int i)
    {
        if(target==0)
        {
            res.push_back(subset);
            return;
        }
        if(i<0)
        {
            return;
        }
        int countt=1;
        if(candidates[i]<=target)
        {
            subset.push_back(candidates[i]);
            ans(candidates, target-candidates[i], subset, i-1);
            subset.pop_back();
        }
        while(i>0 && candidates[i]==candidates[i-1])
        {
            countt++;
            i--;
        }
        ans(candidates, target, subset, i-1);
        return;

    }
    vector<vector<int>> combinationSum2(vector<int>& candidates, int target) {

        vector<int> subset;
        sort(candidates.begin(), candidates.end());
        n = candidates.size();
        ans(candidates, target, subset, candidates.size()-1);
        return res;

    }
};
20769