[Heap] 디스크 컨트롤러

프로그래머스

 

문제: https://school.programmers.co.kr/learn/courses/30/lessons/42627

풀이: https://geunzrial.tistory.com/37

 

import java.util.Arrays;
import java.util.PriorityQueue;

class Solution {
    
    private int finishedCount = 0; // 처리한 작업
    private int time = 0; // 하나의 job이 끝나는 시간
    
    public int solution(int[][] jobs) {
        int answer = 0;
        
        Arrays.sort(jobs, (o1, o2) -> {
            if(o1[0] <= o2[0]) return -1;
            return 1;
        });
        
        PriorityQueue<int[]> pq = new PriorityQueue<>((o1, o2) -> {
            if(o1[1] <= o2[1]) return -1;
            return 1;
        });
        
        int i=0;
        while(finishedCount < jobs.length) {
                        
            while(i < jobs.length && jobs[i][0] <= time) {
                pq.add(jobs[i++]);
            }
            
            if(pq.isEmpty()) {
                time = jobs[i][0];
            }
            else {
                int[] job = pq.poll();
                answer += time - job[0] + job[1];
                time += job[1];
                finishedCount++;    
            }
        }
        
        return answer/jobs.length;
    }
    
}

 

 

 

Comparator 람다형태

Arrays.sort(jobs, new Comparator<int[]>() {
            @Override
            public int compare(int[] o1, int[] o2) {
                if(o1[0] <= o2[0]) return -1;
                return 1;
            }
        });
        
        Arrays.sort(jobs, (o1, o2) -> {
            if(o1[0] <= o2[0]) return -1;
            return 1;
        });

        PriorityQueue<int[]> pq = new PriorityQueue<>(new Comparator<int[]>() {
            @Override
            public int compare(int[] o1, int[] o2) {
                if(o1[1] <= o2[1]) return -1;
                return 1;
            }
        });

        PriorityQueue<int[]> pq2 = new PriorityQueue<>((o1, o2) -> {
            if(o1[1] <= o2[1]) return -1;
            return 1;
        });