看了几遍才知道啥意思。。例如:25^2 = 625,尾数25
自守数
https://www.nowcoder.com/practice/88ddd31618f04514ae3a689e83f3ab8e
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); int n = scanner.nextInt(); int count = 0; for (int i = 0; i <= n; i++) { String naturalNumber = String.valueOf(i); // 自然数的平方 String powString = String.valueOf((int) Math.pow(i, 2)); // 切割尾数 String substring = powString.substring(powString.length() - naturalNumber.length()); if (substring.equals(naturalNumber)) { count++; } } System.out.println(count); } }