구름 LEVEL : 완벽한 햄버거 만들기

문제

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

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));
		StringTokenizer st = new StringTokenizer(br.readLine(), " ");
		
		int N = Integer.parseInt(st.nextToken());
		int arr[] = new int[N];
		int max = Integer.MIN_VALUE;
		int answer = 0;
		boolean flag = false;
		
		st = new StringTokenizer(br.readLine(), " ");
		for(int i = 0; i < N; i++){
			arr[i] = Integer.parseInt(st.nextToken());
			if(max < arr[i]){
				max = arr[i];
			}
		}
		
		answer = arr[N - 1];
		for(int i = 0; i < N - 1; i++){
			int now = arr[i];
			int next = arr[i + 1];
			if(now == max){
				flag = !flag;
			}
			if(!flag){
				if(now > next && now != max){
					answer = 0;
					break;
				}
			} else{
				if(now < next && now != max){
					answer = 0;
					break;
				}
			}
			answer += now;
		}
		
		bw.write(String.valueOf(answer));
		bw.flush();
		
		br.close();
		bw.close();
	}
}

BufferedReader와 BufferedWriter에 적응하자