<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) {
        priority_queue<pair<int, int>> pq;

        if (a) {
            pq.push({a, 'a'});
        }
        if (b) {
            pq.push({b, 'b'});
        }
        if (c) {
            pq.push({c, 'c'});
        }

        string ans = "";
        while (!pq.empty()) {
            auto top = pq.top();
            pq.pop();
            if (ans.size() == 0 || ans.back() != top.second) {
                int times = min(top.first, 2);
                for (int i = 0; i < times; i++) {
                    ans += top.second;
                }
                top.first -= times;
                if (top.first > 0) {
                    pq.push(top);
                }
            } else if (!pq.empty()) {
                auto top2 = pq.top();
                pq.pop();
                ans += top2.second;
                top2.first--;
                if(top2.first > 0){
                    pq.push(top2);
                }
                pq.push(top);
            } else {
                break;
            }
        }
        return ans;
    }
};
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