# 1405. Longest Happy String
###### tags: `Leetcode` `Medium` `Greedy` `Microsoft`
Link: https://leetcode.com/problems/longest-happy-string/
## 思路
每轮放置字符时优先先放剩余次数最多的, 如果上次放的2个字符和剩余个数最多的字符相同，则放置次多的字符
## Code

class Solution {
    public String longestDiverseString(int a, int b, int c) {
        StringBuffer sb = new StringBuffer();
        int[] freq = new int[3];
        freq[0] = a;
        freq[1] = b;
        freq[2] = c;
        Queue<Integer> pq = new PriorityQueue<>((e1,e2)->freq[e2]-freq[e1]);
        if(a!=0) pq.add(0);
        if(b!=0) pq.add(1);
        if(c!=0) pq.add(2);
        while(!pq.isEmpty()){
            int num = pq.poll();
            if(sb.length()>=2 && num==(int)sb.charAt(sb.length()-1)-97 && num==(int)sb.charAt(sb.length()-2)-97){
                if(pq.isEmpty()) break;
                int num2 = pq.poll();
                pq.add(num);
                num = num2;
            }
            sb.append((char)(num+97));
            if(--freq[num]!=0) pq.add(num);
        }
        return sb.toString();
    }
}