<p>Given a string <code>s</code> and a string array <code>dictionary</code>, return <em>the longest string in the dictionary that can be formed by deleting some of the given string characters</em>. If there is more than one possible result, return the longest word with the smallest lexicographical order. If there is no possible result, return the empty string.</p>

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

<pre>
<strong>Input:</strong> s = &quot;abpcplea&quot;, dictionary = [&quot;ale&quot;,&quot;apple&quot;,&quot;monkey&quot;,&quot;plea&quot;]
<strong>Output:</strong> &quot;apple&quot;
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;abpcplea&quot;, dictionary = [&quot;a&quot;,&quot;b&quot;,&quot;c&quot;]
<strong>Output:</strong> &quot;a&quot;
</pre>

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

<ul>
	<li><code>1 &lt;= s.length &lt;= 1000</code></li>
	<li><code>1 &lt;= dictionary.length &lt;= 1000</code></li>
	<li><code>1 &lt;= dictionary[i].length &lt;= 1000</code></li>
	<li><code>s</code> and <code>dictionary[i]</code> consist of lowercase English letters.</li>
</ul>

class Solution {
public:
string findLongestWord(string s, vector<string>& dictionary) {
        string ans = "";
    sort(dictionary.begin(), dictionary.end());
    map<char, vector<int>> positionsChar;
    for(int i = 0; i<s.size(); i++){
        positionsChar[s[i]].push_back(i);
    }
    for(string word : dictionary){
        int currentPosition = -1;
        bool validWord = true;
        for(char c : word){
            auto vectPos = positionsChar[c];
            auto pos = upper_bound(vectPos.begin(), vectPos.end(), currentPosition);
            if(pos!=vectPos.end()){
                currentPosition = *pos;
            } else{
                validWord=false;
                break;
            }
        }
        if(validWord && word.size() > ans.size()){
            ans = word;
        }
    }
    return ans;
}
};
32676