백준 5단계(4344)

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.StringTokenizer;
 
public class Main {
    public static void main(String[] args) throws Exception{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        
        int n = Integer.parseInt(br.readLine());
        String str = null;
        int[][] numArr = new int[n][];
        String[] temp = new String[n];
        
        //receives inputs and saves into temp as string
        int esc = 0;
        while((str = br.readLine()) != null) {
            temp[esc] = str;
            esc++;
            if(esc == n) break;
        }
        //converts string to two-dimesional array int
        for(int i = 0; i < n; i++) {
            StringTokenizer st = new StringTokenizer(temp[i]);
            esc = st.countTokens();
            
            int j = 0;
            numArr[i] = new int[st.countTokens()];
            while(st.hasMoreTokens()) {
                numArr[i][j] = Integer.parseInt(st.nextToken());
                j++;
            }
        }
        
        //find avg, compare and print out  
        for(int i = 0; i < numArr.length; i++) {
            double avg = 0;
            for(int z = 1; z < numArr[i].length; z++) {
                avg += numArr[i][z]; 
            }
            
            avg /= (numArr[i].length - 1);
            int count = 0;
            for(int z = 1; z < numArr[i].length; z++) {
                if(avg < numArr[i][z]) count++;
            }
            avg = (double)count / (numArr[i].length - 1) * 100;
            bw.write(String.format("%.3f", avg) + "%\n");
        }
        bw.flush();
        bw.close();
        br.close();
    }
}

알고리즘을 접근할 때 사용자의 입력값을 당연히 저장해야 되는 줄 알았는데 생각해보니 bufferedwriter의 장점이 flush로 나중에 한 번에 처리가 가능하다는 점을 사용을 못 했네요.

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
 
 
public class Main{
    public static void main(String args[]) throws NumberFormatException, IOException{
        
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        
        int count = Integer.parseInt(br.readLine());
        
        for(int i = 0 ; i < count ; i ++){
            String datas [] = br.readLine().split(" ");
            double sum = 0;
            double avg = 0;
            double tempCnt = 0;
            
            for(int j = 1 ; j < datas.length ; j ++){
                sum += Double.parseDouble(datas[j]);
            }
            avg = (sum / (datas.length -1) );
            
            for(int j = 1 ; j < datas.length ; j ++){
                if(Double.parseDouble(datas[j]) > avg){
                    tempCnt++;
                }
            }
            
            bw.write( String.format("%.3f", (tempCnt / (datas.length -1)) * 100)+"%");
            bw.newLine();
        }
        
        bw.flush();
        bw.close();
        br.close();
    }
}

여기처럼 값을 받자마자 바로 처리하고 값을 다시 받는 식으로 하면 제 코드처럼 굳이 2차원 배열에 안 담고 계산하면 되니

오늘도 배워갑니다!