题解 | #自守数#
自守数
http://www.nowcoder.com/practice/88ddd31618f04514ae3a689e83f3ab8e
观察比较2个字符串的长度，再做截取
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
while(in.hasNextInt()){
int n = in.nextInt();
int sum = 0;
for(int i = 0;i <= n;i++){
String str1 = String.valueOf(i);
String str2 = String.valueOf(i*i);
if(str2.substring(str2.length()-str1.length()).equals(str1)){
sum++;
}
}
System.out.println(sum);
}
}
}