Если есть тест-кейсы вэлкам
package com.javarush.task.task20.task2025;
import java.util.ArrayList;
import java.util.Arrays;
/*
Алгоритмы-числа
*/
public class Solution {
public static long[] getNumbers(long N) {
ArrayList<Long> longsList =new ArrayList<>();
for (int i = 1; i < N; i++) {
if (i > 9) {
String str = Long.toString(i);
int M = str.length();
long S = 0;
for (int k = 0; k < M; k++) {
long number = Long.parseLong(Character.toString(str.charAt(k)));
long preNumb = number;
for (int j = 0; j < M-1; j++) {
number = number * preNumb;
}
S = S + number;
}
if(S == i){
longsList.add(S);
}
} else
longsList.add((long) i);
}
long[] result = new long[longsList.size()];
for (int i = 0; i < longsList.size(); i++) {
result[i] = longsList.get(i);
}
return result;
}
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);
}
}