<p>A string <code>s</code> is called <strong>happy</strong> if it satisfies the following conditions:</p>

<ul>
	<li><code>s</code> only contains the letters <code>&#39;a&#39;</code>, <code>&#39;b&#39;</code>, and <code>&#39;c&#39;</code>.</li>
	<li><code>s</code> does not contain any of <code>&quot;aaa&quot;</code>, <code>&quot;bbb&quot;</code>, or <code>&quot;ccc&quot;</code> as a substring.</li>
	<li><code>s</code> contains <strong>at most</strong> <code>a</code> occurrences of the letter <code>&#39;a&#39;</code>.</li>
	<li><code>s</code> contains <strong>at most</strong> <code>b</code> occurrences of the letter <code>&#39;b&#39;</code>.</li>
	<li><code>s</code> contains <strong>at most</strong> <code>c</code> occurrences of the letter <code>&#39;c&#39;</code>.</li>
</ul>

<p>Given three integers <code>a</code>, <code>b</code>, and <code>c</code>, return <em>the <strong>longest possible happy </strong>string</em>. If there are multiple longest happy strings, return <em>any of them</em>. If there is no such string, return <em>the empty string </em><code>&quot;&quot;</code>.</p>

<p>A <strong>substring</strong> is a contiguous sequence of characters within a string.</p>

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

<pre>
<strong>Input:</strong> a = 1, b = 1, c = 7
<strong>Output:</strong> &quot;ccaccbcc&quot;
<strong>Explanation:</strong> &quot;ccbccacc&quot; would also be a correct answer.
</pre>

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

<pre>
<strong>Input:</strong> a = 7, b = 1, c = 0
<strong>Output:</strong> &quot;aabaa&quot;
<strong>Explanation:</strong> It is the only correct answer in this case.
</pre>

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

<ul>
	<li><code>0 &lt;= a, b, c &lt;= 100</code></li>
	<li><code>a + b + c &gt; 0</code></li>
</ul>

class Solution {
public:
    string longestDiverseString(int a, int b, int c) {
        string ans = "";
        auto custom_cmp = [](pair<int,char>&a,pair<int,char>&b){return a.first < b.first;};
        priority_queue<pair<int,char>,vector<pair<int,char>>,decltype(custom_cmp)> pq(custom_cmp);
        pq.push({a,'a'});
        pq.push({b,'b'});
        pq.push({c,'c'});
        bool flag = true;
        for (;flag;){
            flag = false;
            pair<int,char> first_top = pq.top();
            pq.pop();
            pair<int,char> second_top = pq.top();
            pq.pop();
            int curr_ans_len = ans.length();
            if(curr_ans_len < 2 && first_top.first > 0){
                ans += first_top.second;
                first_top.first--;
                pq.push(first_top);
                pq.push(second_top);
                flag = true;
            }else if (curr_ans_len > 1){
                char second_last_char = ans[curr_ans_len-2];
                char last_char = ans[curr_ans_len-1];
                if (second_last_char == last_char){
                    if(first_top.second == last_char && second_top.first > 0){
                        ans += second_top.second;
                        second_top.first--;
                        flag = true;
                    }else if (first_top.second != last_char && first_top.first > 0){
                        ans += first_top.second;
                        first_top.first--;
                        flag = true;
                    }
                    if(flag){
                        pq.push(first_top);
                        pq.push(second_top);
                    }
                }else{
                    if(first_top.first > 0){
                        ans += first_top.second;
                        first_top.first--;
                        pq.push(first_top);
                        pq.push(second_top);
                        flag = true;
                    }
                }
            }
        }
        return ans;
    }
};
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