백준 11399 (누적합)

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;

// Press Shift twice to open the Search Everywhere dialog and type show whitespaces,
// then press Enter. You can now see whitespace characters in your code.
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());

    int[] times = new int[N];
    StringTokenizer st = new StringTokenizer(br.readLine());
    for (int i = 0; i < N; i++) {
        times[i] = Integer.parseInt(st.nextToken());
    }

    List<Integer> list = new ArrayList();

    for (int i = 0; i < N; i++) {
        list.add(times[i]);
    }

    Collections.sort(list);
    int sum = 0;
    int total = 0;


    for (Integer integer : list) {
        total += integer;
        sum +=total;
    }
    System.out.println(sum);


}

} 누적합 문제를 풀때는 total,sum 총 두개의 변수를 이용해야한다