守形数

package test01;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String s;
        while ((s = br.readLine()) != null) {
            int x = Integer.parseInt(s);
            String xs = String.valueOf(x);
            String square = String.valueOf(x * x);
            if (square.startsWith(xs, square.length() - xs.length()))
                System.out.println("Yes!");
            else
                System.out.println("No!");
        }
    }
}

import java.util.Scanner;
public class Main{
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        while (sc.hasNext()){
            int n=sc.nextInt();
            isKeepShape(n);
        }
    }

    private static void isKeepShape(int n) {
        String s1=String.valueOf(n);
        String s2=String.valueOf(n*n);
        if (s2.endsWith(s1)){
            System.out.println("Yes!");
        }else {
            System.out.println("No!");
        }
    }
}

import java.util.Scanner;

public class Main {
    public static void main(String args[]){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m=n*n;
        String a = Integer.toString(n);
        String b = Integer.toString(m);
        if(b.substring(1,b.length()).equals(a)){
            System.out.println("Yes!");
        }else {
            System.out.println("No!");
        }
    }
}

import java.util.Scanner;//一个很笨的办法 简单易懂
public class NumTest{
        public static void main(String[] args){
            Scanner sc=new Scanner(System.in);
            while(sc.hasNext()){
                int n=sc.nextInt();
                int b=n*n;
                int temp=0;
                int num=0;
                int j=0;
                int i=0;
                if(n>=2&&n<100) {
                    while (b > 9) {
                        temp = b % 10;
                        b = b / 10;
                        i=j;
                        if(i==0){
                            num=temp;
                        }
                       while(i>0){
                           num+=temp*10;
                           i--;
                       }
                        j++;
                    }
                }
                if(num==n){
                    System.out.println("Yes!");

                }else{
                    System.out.println("No!");
                }
            }
        }
}

这种题目用字符串处理是最好的啦，本弱鸡不会什么特别简洁的Python写法（等等等等），向各位大佬们学习！

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while(in.hasNext()) {
            int n = in.nextInt();
            String s2 = String.valueOf(n);
            String s = n * n + "";
            String s1 = s.substring(s.length() - s2.length(), s.length());
            int temp = Integer.parseInt(s1);
            if(temp == n) {
                System.out.println("Yes!");
            }
            else {
                System.out.println("No!");
            }
        }
    }

}

}

import java.util.*;

public class Main{
    
    public static void main(String[] args){
      	Scanner sc = new Scanner(System.in);
        int i = 0;
        int result = 0;
        while (sc.hasNext()) {
            i = sc.nextInt();
            result = i * i;
            int last = 0;
            if(i >= 10){
                last += result % 10;
                result = result / 10;
                last += (result % 10) * 10;
            } else {
                last += result % 10;
            }
            if(last == i){
                System.out.println("Yes!");
            } else {
                System.out.println("No!");
            }
        }
    }
    
}

import java.util.*;
public class Main
{
	public static void main(String[] args)
	{
		Scanner sc=new Scanner(System.in);
		while(sc.hasNext())
		{
			int n=sc.nextInt();
			int sum=0;
			int i=1;
			int m=n*n;
			for(;m!=0;m/=10)
			{
				int g=m%10;
				g*=i;
				sum+=g;
				if(sum==n)
				{
					System.out.println("Yes!");
					break;
				}
				i*=10;
			}
			if(m==0)
			{
				System.out.println("No!");
			}
		}
	}
}