Longest Happy String

A string is called happy if it does not have any of the strings 'aaa', 'bbb' or 'ccc' as a substring.

Given three integers a, b and c, return any string s, which satisfies following conditions:

s is happy and longest possible.
s contains at most a occurrences of the letter 'a', at most b occurrences of the letter 'b' and at most c occurrences of the letter 'c'.
s will only contain 'a', 'b' and 'c' letters.

If there is no such string s return the empty string "".

Example 1:

Input: a = 1, b = 1, c = 7
Output: "ccaccbcc"
Explanation: "ccbccacc" would also be a correct answer.

Example 2:

Input: a = 2, b = 2, c = 1
Output: "aabbc"

Example 3:

Input: a = 7, b = 1, c = 0
Output: "aabaa"
Explanation: It's the only correct answer in this case.

Constraints:

0 <= a, b, c <= 100
a + b + c > 0

Solution:

class Solution {
    class Node {
        char c;
        int remain;
        int count;
        
        public Node(char c, int remain, int count) {
            this.c = c;
            this.remain = remain;
            this.count = count;
        }
    }
    
    public String longestDiverseString(int a, int b, int c) {
        Node A = new Node('a', a, 0);
        Node B = new Node('b', b, 0);
        Node C = new Node('c', c, 0);
        StringBuilder res = new StringBuilder();
        boolean picked = true;
        while (picked) {
            PriorityQueue<Node> pq = new PriorityQueue<>((n1, n2) -> { return Integer.compare(n2.remain, n1.remain); });
            pq.offer(A);
            pq.offer(B);
            pq.offer(C);
            picked = false;
            while (pq.size() > 0) {
                Node curr = pq.poll();
                if (curr.remain > 0 && curr.count < 2 && !picked) {
                    res.append(curr.c);
                    curr.remain --;
                    curr.count ++;
                    picked = true;
                } else {
                    curr.count = 0;
                }
            }    
        }
        return res.toString();
    }
}