<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) {

        int arr[5] = {0, 0, 0, 0, 0};
        vector<pair<int, bool>> v;
        for(int i = 0; i < croakOfFrogs.size(); ++i) {
            auto index = string("croak").find(croakOfFrogs[i]);
            if(index == string::npos) {
                return -1;
            }
            ++arr[index];
            if(index !=0) {
                if(arr[index - 1] < arr[index]) {
                    return -1;
                }
            }

            if(croakOfFrogs[i] == 'c') {
                v.push_back({i, true});
            } else if(croakOfFrogs[i] == 'k') {
                 v.push_back({ i, false});
            }
        }

      
        int current = 0;
        int maxCount = 0;
        for(int i = 0; i < v.size(); ++i) {
            if(v[i].second) {
                ++current;
            } else {
                --current;
            }
            maxCount = max(maxCount, current);
        }

        bool b = true;
        for(int i = 1; i < 5; ++i) {
            b = b && (arr[i] == arr[i -1]);
        }
        if(!b) {
            return -1;
        }

        return current == 0 ? maxCount : -1;



    }
};
17300