2365. Task Scheduler II

You are given a 0-indexed array of positive integers tasks, representing tasks that need to be completed in order, where tasks[i] represents the type of the ith task.

You are also given a positive integer space, which represents the minimum number of days that must pass after the completion of a task before another task of the same type can be performed.

Each day, until all tasks have been completed, you must either:

• Complete the next task from tasks, or
• Take a break.

Return the minimum number of days needed to complete all tasks.

class Solution {
public:
    long long taskSchedulerII(vector<int>& A, int space) {
        long long res = 0;
        unordered_map<long long, long long> mp;
        for(int i = 0; i < A.size(); i++) {
            if(mp[A[i]] > res) res = mp[A[i]];
            else res++;
            mp[A[i]] = res + space + 1;
        }
        return res;
    }
};