[정렬]2751번 수 정렬하기2

출처 : https://www.acmicpc.net/problem/2751

 

Problem

 

Code 

import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws IOException {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();

        int N = Integer.parseInt(br.readLine());

        ArrayList<Integer> list = new ArrayList<>();

        for (int i = 0; i < N; i++)
            list.add(Integer.parseInt(br.readLine()));

        Collections.sort(list);

        for (int i = 0; i < list.size(); i++)
            sb.append(list.get(i)).append('\n');

        System.out.println(sb);
    }
}

 

Improved Code

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
 
public class Main {
	public static void main(String[] args) throws IOException {
    
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringBuilder sb = new StringBuilder();
		boolean[] arr = new boolean[2000001];	
        
		int N = Integer.parseInt(br.readLine());
        
		for(int i = 0; i < N; i++) 
			arr[Integer.parseInt(br.readLine()) + 1000000] = true;
		
 
		for(int i = 0; i < arr.length; i++) {
			if(arr[i]) 
				sb.append((i - 1000000)).append('\n');	
		}
        
		System.out.print(sb);
	}
}

 

개선된 코드 출처 : https://st-lab.tistory.com/106

 

계수정렬을 사용하여 해결한 코드