<p>You are given a <strong>0-indexed</strong> string <code>s</code> and a dictionary of words <code>dictionary</code>. You have to break <code>s</code> into one or more <strong>non-overlapping</strong> substrings such that each substring is present in <code>dictionary</code>. There may be some <strong>extra characters</strong> in <code>s</code> which are not present in any of the substrings.</p>

<p>Return <em>the <strong>minimum</strong> number of extra characters left over if you break up </em><code>s</code><em> optimally.</em></p>

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

<pre>
<strong>Input:</strong> s = &quot;leetscode&quot;, dictionary = [&quot;leet&quot;,&quot;code&quot;,&quot;leetcode&quot;]
<strong>Output:</strong> 1
<strong>Explanation:</strong> We can break s in two substrings: &quot;leet&quot; from index 0 to 3 and &quot;code&quot; from index 5 to 8. There is only 1 unused character (at index 4), so we return 1.

</pre>

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

<pre>
<strong>Input:</strong> s = &quot;sayhelloworld&quot;, dictionary = [&quot;hello&quot;,&quot;world&quot;]
<strong>Output:</strong> 3
<strong>Explanation:</strong> We can break s in two substrings: &quot;hello&quot; from index 3 to 7 and &quot;world&quot; from index 8 to 12. The characters at indices 0, 1, 2 are not used in any substring and thus are considered as extra characters. Hence, we return 3.
</pre>

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

<ul>
	<li><code>1 &lt;= s.length &lt;= 50</code></li>
	<li><code>1 &lt;= dictionary.length &lt;= 50</code></li>
	<li><code>1 &lt;= dictionary[i].length &lt;= 50</code></li>
	<li><code>dictionary[i]</code>&nbsp;and <code>s</code> consists of only lowercase English letters</li>
	<li><code>dictionary</code> contains distinct words</li>
</ul>

class Solution {
public:
    struct TrieNode{
        struct TrieNode* next[26];
        bool flag;
        TrieNode()
        {
            for(int i=0;i<26;i++)
                this->next[i]=NULL;
            this->flag=false;
        }
        

    };
    struct TrieNode* root=new TrieNode();
    void insert(struct TrieNode* root,string s)
    {
        struct TrieNode* node=root;
        for(auto x:s)
        {
            if(node->next[x-'a']==NULL)
                node->next[x-'a']=new TrieNode();
            node=node->next[x-'a'];
        }
        node->flag=true;
    }

    bool search(struct TrieNode* root,string s)
    {
        struct TrieNode* node=root;
        for(auto x:s)
        {
            if(node->next[x-'a']==NULL)
                return false;
            node=node->next[x-'a'];
        }
        if(node->flag==true)
            return true;
        return false;
    }

    int minExtraChar(string s, vector<string>& dictionary) {
        for(auto x:dictionary)
            insert(root,x);
        vector<int>dp(s.length()+1,INT_MIN);
        dp[0]=0;
        for(int i=1;i<=s.length();i++)
        {
            dp[i]=dp[i-1]+1;
            for(int j=1;j<=i;j++)
            {
                if(search(root,s.substr(i-j,j)))
                    dp[i]=min(dp[i],dp[i-j]);
            }
        }
        return dp[s.length()];

    }
};
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