Массив отсортирован и там лежат числа Армстронга не учитывая N
В консоли пишет:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 153, 370, 371, 407]
memory 418
time = 0
[1, 2, 3, 4, 5, 6, 7, 8, 9, 153, 370, 371, 407, 1634, 8208, 9474, 54748, 92727, 93084, 548834]
memory 391
time = 0
package com.javarush.task.task20.task2025;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/*
Алгоритмы-числа
*/
public class Solution {
private static long[][] matrix = new long[10][20];
static {
for (int i = 0; i < 10; i++) {
for (int j = 0; j < 20; j++) {
matrix[i][j] = Math.round(Math.pow(i, j));
}
}
}
public static long[] getNumbers(long N) {
if (N <= 0) return new long[0];
List<Long> list = new ArrayList<>();
for (long i = N - 1; i > 0 ; i--) {
if (isArmstrong(i)){
list.add(i);
}
}
long[] result = new long[list.size()];
int i = 0;
while (!list.isEmpty()){
result[i++] = list.remove(list.size() - 1);
}
return result;
}
private static boolean isArmstrong(long i) {
long temp = i;
int length = String.valueOf(temp).length();
long step, sum = 0L;
while (temp > 0) {
step = temp%10;
temp = temp/10;
sum = sum + matrix[(int)step][length];
}
return i == sum;
}
public static void main(String[] args) {
long a = System.currentTimeMillis();
System.out.println(Arrays.toString(getNumbers(1000)));
long b = System.currentTimeMillis();
System.out.println("memory " + (Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory()) / (8 * 1024));
System.out.println("time = " + (b - a) / 1000);
a = System.currentTimeMillis();
System.out.println(Arrays.toString(getNumbers(1000000)));
b = System.currentTimeMillis();
System.out.println("memory " + (Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory()) / (8 * 1024));
System.out.println("time = " + (b - a) / 1000);
}
}