魔方码（java）

Question

我的Magic Square代码一直存在问题。它不断地打印出“这是一个神奇的广场”，即使我很肯定它不是。 输入16个整数，然后代码应运行并确定输入的整数是否创建一个魔术方（即所有行，列和对角线的总和都相等）。

我无法弄清楚如何让它打印错误。

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.");

    }

}

Answer 1

您的代码中存在许多问题，如评论中所述。

首先，您只需要验证main and secondary diagonals。

其次，比较总和的代码并不适用于所有情况，也不会比较对角线。

另外，if到底是错的。这样做：

if (bool) {
} else {
}

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.");

此外，您可以采取一些措施来优化此代码。