Q2167. 2차원 배열의 합

값들의 합을 저장하며 나아가는 로직.

array[0][0]부터 array[i][j]까지의 합 : sumArray[i][j] = sumArray[i-1][j] + array[i][j] + sumArray[i][j-1] - sumArray[i-1][j-1];

array[y1][x1]부터 array[y2][x2]까지의 합 : sumArray[y2][x2] - sumArray[y1-1][x2] - sumArray[y2][x1-1] + sumArray[y1-1][x1-1];

import java.io.BufferedReader; import java.io.InputStreamReader; import java.util.StringTokenizer; public class Q2167 { static long[][] array; static long[][] sumArray; public static void main(String[] args) throws Exception { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(br.readLine()); int y = Integer.valueOf(st.nextToken()); int x = Integer.valueOf(st.nextToken()); array = new long[y+1][x+1]; sumArray = new long[y+1][x+1]; for (int i = 1; i <= y; i++) { st = new StringTokenizer(br.readLine()); for (int j = 1; j <= x; j++) { array[i][j] = Integer.valueOf(st.nextToken()); sumArray[i][j] = sumArray[i-1][j] + array[i][j] + sumArray[i][j-1] - sumArray[i-1][j-1]; } } st = new StringTokenizer(br.readLine()); int num = Integer.valueOf(st.nextToken()); for (int n = 1; n <= num; n++) { st = new StringTokenizer(br.readLine()); int y1 = Integer.valueOf(st.nextToken()); int x1 = Integer.valueOf(st.nextToken()); int y2 = Integer.valueOf(st.nextToken()); int x2 = Integer.valueOf(st.nextToken()); long sum = sumArray[y2][x2] - sumArray[y1-1][x2] - sumArray[y2][x1-1] + sumArray[y1-1][x1-1]; System.out.println(sum); } } }