Question

我编写了一个代码，用于检查数字是否为幸福素数。快乐的数字是these types of numbers.

以下是一个幸福号码的示例：

最后我们得到“1”，这意味着它是一个幸福的素数。

发现我的错误，感谢@resueman但仍有一个问题。它不打印第四个输入的输出“4 1000”

新代码是：

   import java.io.*;

public class Contest {

public static void main(String[] args) throws IOException {

        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

        int n = Integer.parseInt(reader.readLine());
        for(int m =n; m>0; m--)
        {
            String s = reader.readLine();
            String[] sa = s.split(" ");
            String number = sa[1];
            int squareNumber;
            int orignialNum = Integer.parseInt(number);

            boolean isPrime = true;
            for(int i=2; i<=orignialNum/2;i++)
            {
                if(orignialNum % i == 0){
                    isPrime = false;
                }

            }
            if(isPrime)
            {
                if(orignialNum == 0 || orignialNum == 1 || orignialNum == 2 || orignialNum == 3)
                {
                    System.out.println(sa[0]+" "+orignialNum+" "+"No");
                }
                else
                {
                    squareNumber = orignialNum;
                    if(orignialNum<10){
                        squareNumber = orignialNum*orignialNum;
                    }

                    int newNumber = check(squareNumber);


                    boolean isHappyNumber = isHappy(newNumber);
                    if(isHappyNumber)
                    {
                        System.out.println(sa[0]+" "+orignialNum+" "+"Yes");
                    }
                    else
                    {
                        System.out.println(sa[0]+" "+orignialNum+" "+"No");
                    }
                }
            }
            else
            {
                System.out.println(sa[0]+" "+orignialNum+" "+"No");
            }

        }

}
public static boolean isHappy(int n)
{
    if(n==1)
    {
        return true;
    }
    else
    {
        return false;
    }
}
public static int check(int n)
{
        if(n>9)
        {
            String sm = String.valueOf(n);
            String[] m = sm.split("");
            int[] a = new int[m.length];
            for(int i =0; i<a.length; i++)
            {
                a[i]= Integer.parseInt(m[i]);

            }

            for(int i =0; i<a.length; i++)
            {
                a[i]= a[i]*a[i];

            }
            int sum = 0;

            for(int i =0; i<a.length; i++)
            {
                sum = sum+a[i];
            }
            return check(sum);
        }
        else
        {
            return n;
        }
}
}

第一行将获取执行时所需的输入数量。

我提供的输入是：

我得到的输出：

1 1 No
2 7 Yes
3 383 No

预期的输出是：

1 1 NO
2 7 YES
3 383 YES
4 1000 NO

不知何故，第4个输出没有出现，而“383”则没有出现显示没有。

请帮忙。

Answer 1

我稍微重构了你的代码并提出了这个问题。

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

public class Main {

    public static void main(String[] args) throws IOException {
        int numInputs = 0;
        BufferedReader reader;

        reader = new BufferedReader(new InputStreamReader(System.in));
        numInputs = Integer.parseInt(reader.readLine());

        for(; numInputs > 0; numInputs -= 1) {
            String line = reader.readLine();
            String[] splitLine = line.split(" ");
            int number = Integer.parseInt(splitLine[1]);

            if(isPrime(number)) {
                if(number == 2 || number == 3) {
                    System.out.format("%s %d No\n", splitLine[0], number);
                } else {
                    if(isHappy(number)) {
                        System.out.format("%s %d Yes\n", splitLine[0], number);
                    } else {
                        System.out.format("%s %d No\n", splitLine[0], number);
                    }
                }
            } else {
                System.out.format("%s %d No\n", splitLine[0], number);
            }

        }

    }

    private static boolean isPrime(int n) {
        if (n <= 1) return false;
        if (n == 2 || n == 3) return true;

        if (n % 2 == 0 || n % 3 == 0) {
        // If multiple of 2 or 3 it's not a prime
            return false;
        }

        // Search for divisors from 5 to only sqrt(n)
        // Example: 36: (1*36) (2*18) (3*12) (6*6) (12*3) (18*2) (36*1)
        for ( int i = 5; i * i <= n; i += 6 ) {
            // Check only odd numbers
            if ( n % i == 0 || n % ( i + 2 ) == 0 ) {
                // i+4 is not checked cause it's a multiple of 3
                // i is increased by 6 (multiple of 3) and the first i+4 = 9
                return false;
            }
        }

        return true;
    }

    private static boolean isHappy(int n) {
        do {
            int sum = 0;

            // While number n has two or more digits
            while( n / 10 != 0 ) { 
                int remainder = n % 10;         // last digit
                n = n / 10;                     // n without last digit
                sum += remainder * remainder;
            }
            sum += n * n;                       // add square of the last digit
            n = sum;
        } while(n != 1 && n != 4);              // n == 1 => :) n == 4 => :(

        return n == 1;
    }
}

检查号码是否为快乐素数

1 个答案: