find_min_time_period.cpp

int FindMinTimePeriod(const vector<int>& tasks, int K) {
	unordered_map<int, int> task_to_last_time;
	int cur_time = 0;
	for (int i = 0; i < tasks.size(); ++i) {
		int cur_task = tasks[i];
		auto it = task_to_last_time.find(cur_task);
		if (it != task_to_last_time.end()) {
			cur_time = max(cur_time, it->second + K + 1);
			it->second = cur_time;
		} else {
			task_to_last_time[cur_task] = cur_time;
	}
		++cur_time;
	}
	return cur_time;
} // time: O(n), space: O(num different tasks)