코딩테스트 보기 전 보고들어갈 것

• int[] a 역순정렬 Arrays.stream(a).boxed().sorted(Comparator.reverseOrder()).mapToInt(Integer::intValue).toArray();
• String[] a를 int[]배열로 Arrays.stream(a).mapToInt(Integer::parseInt).toArray();
• 객체 정렬

public class People implements Comparable<People>{
	String name;
    int age;
    
    People(String name, int age){
    	this.name = name;
        this.age = age;
    }
    
    @Override
    public int compareTo(People people){
    	if(this.age > people.age){
        	return 1;
        }else if(this.age == people.age){
        	return 0;
        }else{
        	return -1;
        }
    }
}