暴力解法
import java.util.Scanner;
public class NeighborAvgOld {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int L = sc.nextInt();
int r = sc.nextInt();
int t = sc.nextInt();
sc.nextLine();
int[][] arr = new int[n][n];
int[][] sum_arr = new int[n+1][n+1];
for(int i = 0; i < n; i++){
String line = sc.nextLine();
String[] str_arr = line.split(" ");
for(int j = 0; j < n; j++){
arr[i][j] = Integer.parseInt(str_arr[j]);
sum_arr[i+1][j+1] = sum_arr[i][j+1] + sum_arr[i+1][j]
- sum_arr[i][j] + arr[i][j];
}
}
int total_count = 0;
for(int i = 0; i < n; i++){
for(int j = 0; j < n; j++){
int tmp_sum = 0;
int count = 0;
for(int a = i-r; a <= i+r; a++){
for(int b = j-r; b <= j+r; b++){
if(a >= 0 && a < n && b >= 0 && b < n){
tmp_sum+=arr[a][b];
count++;
}
}
}
if(count!=0&&tmp_sum<=t*count){
total_count++;
}
}
}
System.out.println(total_count);
}
}
二维前缀和
原理参考:
https://blog.csdn.net/m0_65998513/article/details/132534198
import java.util.Scanner;
public class NeighborAvg {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int L = sc.nextInt();
int r = sc.nextInt();
int t = sc.nextInt();
sc.nextLine();
int[][] arr = new int[n][n];
int[][] sum_arr = new int[n+1][n+1];
for(int i = 0; i < n; i++){
String line = sc.nextLine();
String[] str_arr = line.split(" ");
for(int j = 0; j < n; j++){
arr[i][j] = Integer.parseInt(str_arr[j]);
sum_arr[i+1][j+1] = sum_arr[i][j+1] + sum_arr[i+1][j]
- sum_arr[i][j] + arr[i][j];
}
}
int total_count = 0;
for(int i = 1; i <= n; i++){
for(int j = 1; j <= n; j++){
int X1 = i-r >= 1 ? i-r : 1;
int Y1 = j-r >= 1 ? j-r : 1;
int X2 = i+r <= n ? i+r : n;
int Y2 = j+r <= n ? j+r : n;
int p = sum_arr[X2][Y2] - sum_arr[X2][Y1 -1] - sum_arr[X1-1][Y2] + sum_arr[X1-1][Y1 -1];
if(p <= (X2- X1 + 1)*(Y2 - Y1 + 1)* t) total_count++;
}
}
System.out.println(total_count);
}
}