백준 11650 좌표 정렬하기

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
StringTokenizer st = new StringTokenizer(br.readLine());
StringBuilder sb = new StringBuilder();
를 써서 시간을 최대한 줄여줘야했던 문제였다.

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

public class Main {
    public static void main(String[] args) throws IOException {
        // TODO Auto-generated method stub
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());
        int N = Integer.parseInt(st.nextToken());
        int M = Integer.parseInt(st.nextToken());
        int num[][] = new int[N+1][N+1];


        for(int i = 1; i<N+1; i++) {
            st = new StringTokenizer(br.readLine());
            for(int j=1; j<N+1; j++) {
                num[i][j]=num[i][j-1]+Integer.parseInt(st.nextToken());
            }

        }
        StringBuilder sb = new StringBuilder();
        for(int i=0; i<M; i++) {
            st = new StringTokenizer(br.readLine());
            int x1 = Integer.parseInt(st.nextToken());
            int y1 = Integer.parseInt(st.nextToken());
            int x2 = Integer.parseInt(st.nextToken());
            int y2 = Integer.parseInt(st.nextToken());
            int sum=0;

                for(int k=x1; k<=x2; k++) {
                    sum=sum+num[k][y2]-num[k][y1-1];
                }
                sb.append(sum+"\n");

        }
        System.out.println(sb);
    }
}