任务调度器

/*
 * 题目思路：
 * 利用 Java Stream API 简化代码逻辑。我们依然需要统计每种任务的频率，
 * 然后计算最短时间。与传统 Java 方法相比，Stream 提供了更简洁的代码风格。
 */
 
import java.util.*;
import java.util.stream.Collectors;
 
public class Solution {
    public int leastInterval(char[] tasks, int n) {
        Map<Character, Long> freqMap = Arrays.stream(tasks)
                .boxed()
                .collect(Collectors.groupingBy(c -> c, Collectors.counting()));
        List<Long> frequencies = new ArrayList<>(freqMap.values());
        Collections.sort(frequencies, Collections.reverseOrder());
        long maxCount = frequencies.get(0);
        long idleSlots = (maxCount - 1) * n;
        for (long freq : frequencies) {
            idleSlots -= Math.min(maxCount - 1, freq);
        }
        return (int) (idleSlots > 0 ? idleSlots + tasks.length : tasks.length);
    }
}