Description

Submission

class Solution {
public:
    string longestDiverseString(int a, int b, int c) {
        typedef pair<int, char> PIC;
        set<PIC, greater<>> Set;
        if(a)
            Set.insert({a, 'a'});
        if(b)
            Set.insert({b, 'b'});
        if(c)
            Set.insert({c, 'c'});
        
        string ret = "";

        while(!Set.empty()) {
            auto iter = Set.begin();
            for(; iter != Set.end(); ++iter) {
                if(!ret.empty() && iter->second == ret.back()) continue;
                if(iter == Set.begin()) {
                    if(iter->first >= 2) {
                        PIC p {iter->first - 2, iter->second};
                        Set.erase(iter);
                        ret.push_back(p.second);
                        ret.push_back(p.second);
                        if(p.first != 0)
                            Set.insert(p);
                    } else {
                        ret.push_back(iter->second);
                        Set.erase(iter);
                    }
                    
                } else {
                    PIC p {iter->first - 1, iter->second};
                    Set.erase(iter);
                    ret.push_back(p.second);
                    if(p.first != 0)
                        Set.insert(p);
                    
                }
                break;
                
            }
            if(Set.size() == 1 && Set.begin()->second == ret.back()) break;
        }
        
        return ret;
    }
};

Submission 210811

class Solution {
public:
    string longestDiverseString(int a, int b, int c) {
        typedef pair<int, char> PIC;
        priority_queue<PIC, vector<PIC>, less<>> pq;

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

        string ret = "";
        while(!pq.empty()) {
            if(pq.size() == 1) {
                for(int i = 0; i < min(pq.top().first, 2); ++i) {
                    ret.push_back(pq.top().second);
                }
                return ret;
            }

            auto [cnt1, ch1] = pq.top();
            pq.pop();
            auto [cnt2, ch2] = pq.top();
            pq.pop();

            int k = min(cnt1 - cnt2 + 1, 2);
            cnt1 -= k;
            while(k--) {
                ret.push_back(ch1);
            }
            cnt2 -= 1;
            ret.push_back(ch2);
            

            if(cnt1) pq.push({cnt1, ch1});
            if(cnt2) pq.push({cnt2, ch2});
        }

        return ret;
    }
};