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List 정렬하는법
//기본 오름차순
Collections.sort(list);
//내림차순
Collections.sort(names, Collections.reverseOrder());
//person 객체의 age로 정렬하기
Collections.sort(list,Comparator.comparingInt(person -> person.age))
//문자열의 길이를 기준으로 정렬
Collections.sort(names, Comparator.comparingInt(String::length));
import java.util.*;
class Solution {
public int[][] solution(int[][] data, String ext, int val_ext, String sort_by) {
HashMap<String,Integer> columnInfo= new HashMap<>();
columnInfo.put("code",0);
columnInfo.put("date",1);
columnInfo.put("maximum",2);
columnInfo.put("remain",3);
//조건 인덱스
int extIndex = columnInfo.get(ext);
//정렬 인덱스
int sortIndex = columnInfo.get(sort_by);
List<int[]> newData = new ArrayList<>();
for(int i=0;i<data.length;i++){
int[] detailData = data[i];
//조건부합하는지 검사
if(detailData[extIndex] < val_ext){
newData.add(detailData);
}
}
//List 정렬
Collections.sort(newData,Comparator.comparingInt(list->list[sortIndex]));
//Collections.sort(newData,(a,b)->Integer.compare(a[sortIndex],b[sortIndex]));
int[][] answer = new int[newData.size()][4];
answer = newData.toArray(new int[0][]);
return answer;
}
}반응형
