<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>

class Solution {
public:
    int solve(vector<vector<int>> &nums, unordered_map<string, int> &dp, string target) {
        if (dp.find(target) != dp.end()) {
            return dp[target];
        }
        int ans = INT_MAX;
        int n = nums.size();
        vector<int> target_count(26, 0);
        for (auto c: target) {
            target_count[c - 'a']++;
        }
        for (int i = 0; i < n; i++) {
            //if (nums[i][target[0] - 'a'] == 0) continue;
            bool flag = false;
            for (auto c: target) {
                if (nums[i][c - 'a'] != 0) {
                    flag = true;
                    break;
                }
            }
            if (!flag) continue;
            string sub_target = "";
            for (int j = 0; j < 26; j++) {
                if (target_count[j] - nums[i][j] > 0) {
                    sub_target += string(target_count[j] - nums[i][j], 'a' + j);
                }
            }
            // aeht
            // ae
            cout << sub_target << "\n";
            ans = min(ans, solve(nums, dp, sub_target) + 1);
        }
        dp[target] = ans;
        return dp[target];

    }
    int minStickers(vector<string>& stickers, string target) {
        int n = stickers.size();
        vector<vector<int>> nums(n, vector<int>(26, 0));
        vector<int> total_nums(26, 0);
        for (int i = 0; i < n; i++) {
            for (auto c: stickers[i]) {
                nums[i][c - 'a']++;
                total_nums[c - 'a']++;
            }
        }
        
        for (auto c: target) {
            if (total_nums[c - 'a'] == 0)
                return -1;
        }

        unordered_map<string, int> dp;
        dp[""] = 0;
        //dp[string] = i, form string needs i stickers
        int ans = solve(nums, dp, target);
        return ans;
    }
};
30458