Description

Submission

class Solution {
    typedef pair<int, int> PII;
    int cnt[26];
public:
    int leastInterval(vector<char>& tasks, int n) {
        priority_queue<PII, vector<PII>> pq;

        for(auto ch: tasks) {
            ++cnt[ch-'A'];
        }

        for(int i = 0; i < 26; ++i) {
            if(cnt[i]) pq.push({cnt[i], i});
        }

        int ret = 0;
        while(!pq.empty()) {
            vector<int> tmp(26, 0);
            int pqSize = pq.size();
            for(int i = 0; !pq.empty() && i < n + 1; ++i) {
                auto [count, index] = pq.top();
                pq.pop();

                count -= 1;
                if(count) tmp[index] = count;
            }

            for(int i = 0; i < 26; ++i) {
                if(tmp[i]) pq.push({tmp[i], i});
            }
            if(pq.empty()) ret += pqSize;
            else ret += n + 1;
        }

        return ret;
    }
};