<p>You are given the string <code>croakOfFrogs</code>, which represents a combination of the string <code>&quot;croak&quot;</code> from different frogs, that is, multiple frogs can croak at the same time, so multiple <code>&quot;croak&quot;</code> are mixed.</p>

<p><em>Return the minimum number of </em>different<em> frogs to finish all the croaks in the given string.</em></p>

<p>A valid <code>&quot;croak&quot;</code> means a frog is printing five letters <code>&#39;c&#39;</code>, <code>&#39;r&#39;</code>, <code>&#39;o&#39;</code>, <code>&#39;a&#39;</code>, and <code>&#39;k&#39;</code> <strong>sequentially</strong>. The frogs have to print all five letters to finish a croak. If the given string is not a combination of a valid <code>&quot;croak&quot;</code> return <code>-1</code>.</p>

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

<pre>
<strong>Input:</strong> croakOfFrogs = &quot;croakcroak&quot;
<strong>Output:</strong> 1 
<strong>Explanation:</strong> One frog yelling &quot;croak<strong>&quot;</strong> twice.
</pre>

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

<pre>
<strong>Input:</strong> croakOfFrogs = &quot;crcoakroak&quot;
<strong>Output:</strong> 2 
<strong>Explanation:</strong> The minimum number of frogs is two. 
The first frog could yell &quot;<strong>cr</strong>c<strong>oak</strong>roak&quot;.
The second frog could yell later &quot;cr<strong>c</strong>oak<strong>roak</strong>&quot;.
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> croakOfFrogs = &quot;croakcrook&quot;
<strong>Output:</strong> -1
<strong>Explanation:</strong> The given string is an invalid combination of &quot;croak<strong>&quot;</strong> from different frogs.
</pre>

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

<ul>
	<li><code>1 &lt;= croakOfFrogs.length &lt;= 10<sup>5</sup></code></li>
	<li><code>croakOfFrogs</code> is either <code>&#39;c&#39;</code>, <code>&#39;r&#39;</code>, <code>&#39;o&#39;</code>, <code>&#39;a&#39;</code>, or <code>&#39;k&#39;</code>.</li>
</ul>

class Solution {
public:
    int minNumberOfFrogs(string croakOfFrogs) {
        unordered_map<char, int>mp;
        mp['c'] = 0;
        mp['r'] = 0;
        mp['o'] = 0;
        mp['a'] = 0;
        mp['k'] = 0;

        int maxFrogs = 0;
        int frogs = 0;

        for(int i = 0;i<croakOfFrogs.length();i++){
            if(croakOfFrogs[i] == 'c'){
                mp['c']++;
                frogs++;
                maxFrogs = max(maxFrogs, frogs);
            }
            if(croakOfFrogs[i] == 'r'){
                if(mp['c'] == 0) return -1;
                mp['r']++;
                mp['c']--;
            }
            if(croakOfFrogs[i] == 'o'){
                if(mp['r'] == 0) return -1;
                mp['o']++;
                mp['r']--;
            }
            if(croakOfFrogs[i] == 'a'){
                if(mp['o'] == 0) return -1;
                mp['a']++;
                mp['o']--;
            }
            if(croakOfFrogs[i] == 'k'){
                if(mp['a'] == 0) return -1;
                mp['a']--;
                frogs--;
            }
        }

        if(mp['c'] == 0 && mp['r'] == 0 && mp['o'] == 0 && mp['a'] == 0 && mp['k'] == 0) return maxFrogs;
        return -1;
    }
};
12000