<p>We are given <code>n</code> different types of <code>stickers</code>. Each sticker has a lowercase English word on it.</p>

<p>You would like to spell out the given string <code>target</code> by cutting individual letters from your collection of stickers and rearranging them. You can use each sticker more than once if you want, and you have infinite quantities of each sticker.</p>

<p>Return <em>the minimum number of stickers that you need to spell out </em><code>target</code>. If the task is impossible, return <code>-1</code>.</p>

<p><strong>Note:</strong> In all test cases, all words were chosen randomly from the <code>1000</code> most common US English words, and <code>target</code> was chosen as a concatenation of two random words.</p>

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

<pre>
<strong>Input:</strong> stickers = [&quot;with&quot;,&quot;example&quot;,&quot;science&quot;], target = &quot;thehat&quot;
<strong>Output:</strong> 3
<strong>Explanation:</strong>
We can use 2 &quot;with&quot; stickers, and 1 &quot;example&quot; sticker.
After cutting and rearrange the letters of those stickers, we can form the target &quot;thehat&quot;.
Also, this is the minimum number of stickers necessary to form the target string.
</pre>

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

<pre>
<strong>Input:</strong> stickers = [&quot;notice&quot;,&quot;possible&quot;], target = &quot;basicbasic&quot;
<strong>Output:</strong> -1
Explanation:
We cannot form the target &quot;basicbasic&quot; from cutting letters from the given stickers.
</pre>

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

<ul>
	<li><code>n == stickers.length</code></li>
	<li><code>1 &lt;= n &lt;= 50</code></li>
	<li><code>1 &lt;= stickers[i].length &lt;= 10</code></li>
	<li><code>1 &lt;= target.length &lt;= 15</code></li>
	<li><code>stickers[i]</code> and <code>target</code> consist of lowercase English letters.</li>
</ul>

struct fast
{
    fast()
    {
        ios_base::sync_with_stdio(false);
        cin.tie(NULL);
    }
};
fast go;

class Solution {
public:

    unordered_map<string, int> dp;

    int func(vector<string>& stix, string& currs)
    {
        if(dp.find(currs) != dp.end())
        {
            return dp[currs];
        }
        if(currs.size() == 0) return 0;
        vector<int> curr (27, 0);
        for(auto &it: currs)
        {
            curr[it - 'a']++;
        }
        int ans = 1e9;
        for(auto &it: stix)
        {
            vector<int> temp;
            for(auto &x: it)
            {
                if(curr[x-'a'] > 0)
                {
                    temp.push_back(x-'a');
                    curr[x-'a']--;
                }
            }
            if(0 < temp.size())
            {
                string tt = "";
                for(int i = 0; i<curr.size(); i++)
                {
                    for(int j = 0; j<curr[i]; j++)
                    {
                        tt += i + 'a';
                    }
                }
                ans = min(ans , 1 + func(stix, tt));
            }
            for(auto &y: temp)
            {
                curr[y]++;
            }
        }
        return dp[currs] = ans;
    }


    int minStickers(vector<string>& stickers, string& target) {
        sort(target.begin(), target.end());
        int ans = func(stickers, target);
        if(ans >= 1e9) return -1;
        return ans;
    }
};
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