魔方代码 (java)

Magic Square Code (java)

提问by adlerT16

I've been having an issue with my Magic Square code. It continually prints "This is a magic square" even when I'm positive it isn't. You enter 16 integers, and then the code is supposed to run and determine whether the entered integers create a magic square (i.e. the sum of all rows, columns, and diagonals are all equal).

我的 Magic Square 代码有问题。即使我确定它不是，它也会不断打印“这是一个幻方”。您输入 16 个整数，然后代码应该运行并确定输入的整数是否创建幻方（即所有行、列和对角线的总和都相等）。

I can't figure out how to make it print false.

我不知道如何让它打印假。

import java.util.*;
public class MagicSquare {

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        Scanner keyboard = new Scanner (System.in);

        int [] [] square = new int [4][4];
        for (int row = 0; row < 4; row++)
        {
            for (int col = 0; col < 4; col++)
            {
                System.out.println("Input value for row " + (row+1) + " column " + (col+1));
                square[row][col] = keyboard.nextInt();
            }
        }

        int [] sumRow = new int [4];
        int [] sumCol = new int [4];

        int sum = 0;

        for (int row = 0; row < 4; row ++)
        {
            for (int col = 0; col < 4; col ++)
            {
                sum = sum + square[row][col];
                sumRow[row] = sum;
            }
            System.out.println("sum row " + row + "\n" + sumRow[row]);
            sum = 0;
        }

        sum = 0;

        for (int col = 0; col < 4; col ++)
        {
            for (int row = 0; row < 4; row ++)
            {
                sum = sum + square[row][col];
                sumCol[col] = sum;
            }
            System.out.println("sum columns " + col + "\n" + sumCol[col]);
            sum = 0;
        }

        int [] sumDiag = new int [4];
        sum = 0;

        for (int row = 0; row < 4; row++)
        {
            for (int col = 3; col > -1; col--)
            {
                sum = sum + square [row][col];
                sumDiag[row] = sum;
            }
            System.out.println("sum diagonal " + row + "\n" + sumDiag[row]);
            sum = 0;
        }

        int [] sumDiag2 = new int [4];
        sum = 0; 

        for (int col = 0; col < 4; col ++)
        {
            for (int row = 3; row > -1; row --)
            {
                sum = sum + square[row][col];
                sumDiag2[col] = sum;
            }
            System.out.println("sum diagonal 2 " + col + "\n" + sumDiag2[col]);
        }

        boolean bool = false;

        int k = 0; int j = 1; 
        do
        {
            if (sumRow[k] == sumRow[j])
            {
                k = j;
                j += 1;
                bool = true;
            }
            else
            {
                bool = false;
                System.out.println("Not a magic square");
                break;
            }
        } while ((k < 4) && (j >- 1));

        k = 0; j = 1;
        do
        {
            if (sumCol[k] == sumRow[j])
            {
                k = j;
                j += 1;
                bool = true;
            }
            else 
            {
                bool = false;
                System.out.println("Not a magic square");
                break;
            }
        } while ((k < 4) && (j >= -1));



        String TorF = "";
        if (bool = true)
        {
            TorF = "is";
        }
        else if (bool = false)
        {
            TorF = "is not";
        }

        System.out.println("This " + TorF + " a magic square.");

    }

}

回答by André Luiz Ferreira Pinto

There is a number of issues in your code, as said in the comments.

如评论中所述，您的代码中存在许多问题。

First, you only need to verify the main and secondary diagonals.

首先，您只需要验证主要和次要对角线。

Second, your code to compare the sums doesn't work for all cases and doesn't compare the diagonals.

其次，您用于比较总和的代码不适用于所有情况，并且不会比较对角线。

Also, the ifin the end is just wrong. Do this instead:

还有，if到头来就是错的。改为这样做：

if (bool) {
} else {
}

And here is a solution:

这是一个解决方案：

int order = square.length;

int[] sumRow = new int[order];
int[] sumCol = new int[order];
int[] sumDiag = new int[2];

Arrays.fill(sumRow, 0);
Arrays.fill(sumCol, 0);
Arrays.fill(sumDiag, 0);

for (int row = 0; row < order; row++) {
  for (int col = 0; col < order; col ++) {
    sumRow[row] += square[row][col];
  }
  System.out.println("sum row " + row + "\n" + sumRow[row]);
}

for (int col = 0; col < order; col++) {
  for (int row = 0; row < order; row ++) {
    sumCol[col] += square[row][col];
  }
  System.out.println("sum columns " + col + "\n" + sumCol[col]);
}

for (int row = 0; row < order; row++) {
  sumDiag[0] += square[row][row];
}
System.out.println("sum diagonal 0 " + "\n" + sumDiag[0]);

for(int row = 0; row < order; row++) {
  sumDiag[1] += square[row][order - 1 - row];
}
System.out.println("sum diagonal 1 " + "\n" + sumDiag[1]);

boolean bool = true;

int sum = sumRow[0];
for (int i = 1; i < order; i++) {
  bool = bool && (sum == sumRow[i]);
}
for (int i = 0; i < order; i++) {
  bool = bool && (sum == sumCol[i]);
}
for (int i = 0; i < 2; i++) {
  bool = bool && (sum == sumDiag[i]);
}

String tOrF = "";
if (bool) {
  tOrF = "is";
} else {
  tOrF = "is not";
}
System.out.println("This " + tOrF + " a magic square.");

Furthermore, there are some things you could do to optimize this code.

此外，您可以采取一些措施来优化此代码。