[Java] Priority Queue - Custom 정렬

 

• Class를 활용한 구조체 생성 (Value)
• PriorityQueue Custom 정렬을 위해서 compareTo 활용.
• compareTo 하지 않을경우 Error 발생 ( default int 정렬 )

import java.util.*;

class Value implements Comparable<Value>{
    private int start,time;
    public Value(int start, int time){
        this.start = start;
        this.time = time;
    }
    public int getTime(){
        return this.time;
    }
    public int getStart(){
        return this.start;
    }
    @Override
    public int compareTo(Value target){
        if(this.time>target.time){
            return 1;
        }else if(this.time==target.time){
            return 0;
        }else {
            return -1;
        }        
        //Lambda return this.time >= target.time ? 1 : -1;
    }
}

class Solution {
    public int solution(int[][] jobs) {
        int answer = 0;
        
        ### PriorityQueue ###
        PriorityQueue<Value> pq = new PriorityQueue<Value>();
        
        for(int i=0; i<jobs.length; i++){
            pq.add(new Value(jobs[i][0],jobs[i][1]));
        }
        
        while(!pq.isEmpty()){
            Value tmp = pq.poll(); 
            System.out.println(tmp);
        }
        ### PriorityQueue ###
        
        return answer;
    }
}