1405_Longest_Happy_String.java

class Solution {

        public String longestDiverseString(int a, int b, int c) {
                PriorityQueue<Pair> pq = new PriorityQueue<Pair>((x, y) ->
                            (y.count - x.count)
                                    );
                                            // Add the counts of a, b and c in priority queue.
                                                    if (a > 0) {
                                                                pq.add(new Pair(a, 'a'));
                                                                        }

                                                                                if (b > 0) {
                                                                                            pq.add(new Pair(b, 'b'));
                                                                                                    }

                                                                                                            if (c > 0) {
                                                                                                                        pq.add(new Pair(c, 'c'));
                                                                                                                                }

                                                                                                                                        StringBuilder ans = new StringBuilder();
                                                                                                                                                while (!pq.isEmpty()) {
                                                                                                                                                            Pair p = pq.poll();
                                                                                                                                                                        int count = p.count;
                                                                                                                                                                                    char character = p.character;
                                                                                                                                                                                                // If three consecutive characters exists, pick the second most
                                                                                                                                                                                                            // frequent character.
                                                                                                                                                                                                                        if (
                                                                                                                                                                                                                                        ans.length() >= 2 &&
                                                                                                                                                                                                                                                        ans.charAt(ans.length() - 1) == p.character &&
                                                                                                                                                                                                                                                                        ans.charAt(ans.length() - 2) == p.character
                                                                                                                                                                                                                                                                                    ) {
                                                                                                                                                                                                                                                                                                    if (pq.isEmpty()) break;

                                                                                                                                                                                                                                                                                                                    Pair temp = pq.poll();
                                                                                                                                                                                                                                                                                                                                    ans.append(temp.character);
                                                                                                                                                                                                                                                                                                                                                    if (temp.count - 1 > 0) {
                                                                                                                                                                                                                                                                                                                                                                        pq.add(new Pair(temp.count - 1, temp.character));
                                                                                                                                                                                                                                                                                                                                                                                        }
                                                                                                                                                                                                                                                                                                                                                                                                    } else {
                                                                                                                                                                                                                                                                                                                                                                                                                    count--;
                                                                                                                                                                                                                                                                                                                                                                                                                                    ans.append(character);
                                                                                                                                                                                                                                                                                                                                                                                                                                                }

                                                                                                                                                                                                                                                                                                                                                                                                                                                            // If count is greater than zero, add it to priority queue.
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        if (count > 0) {
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        pq.add(new Pair(count, character));
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    }
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            }
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    return ans.toString();
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        }

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            class Pair {

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    int count;
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            char character;

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    Pair(int count, char character) {
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                this.count = count;
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            this.character = character;
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    }
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        }
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        }