我正在一个项目中，我必须读取文件并将内容输入2D数组。然后，我必须对每一行，每一列和矩阵的周长求和。到目前为止，除外围功能外，我一切正常。我正在尝试为两个外部列的顶行，底行和中间创建单独的for循环。

矩阵文件如下所示：

1 2 3 4

2 4 6 8

2 4 6 8

3 2 3 4

因此，周长总计应为42。现在，我可以成功地将第一行和最后一行添加为等于22。但是，当我将列添加到总数中时，我得到32。

这是代码：

import java.util.*; // Scanner class

import java.io.*; // File class

public class Lab10

{

static public void main( String [ ] args ) throws Exception

{

if ( args.length != 1 )

{

System.out.println("Error -- usage is: java Lab10 matdataN.txt");

System.exit( 0 );

}

//Requirement #1: first int value: # of rows, second int value: # of cols

File newFile = new File(args[0]);

Scanner in = new Scanner(newFile);

int numRows = in.nextInt();

int numCols = in.nextInt();

//Requirement #2: declare two-d array of ints

int[][] matrix;

matrix = new int[numRows][numCols];

//Requirement #3 & 4: read file one line at a time (nested for loops

//and nextInt()) and print

for (int i = 0; i < numRows; i++)

{

for (int j = 0; j < numCols; j++)

{

matrix[i][j] = in.nextInt();

System.out.print(matrix[i][j]+ " ");

}

System.out.println();

}

//Requirement #5: traverse each row and sum the values and display the sums

int rowTotal = 0;

for (int i = 0; i < numRows; i++)

{

rowTotal = 0;

for (int j = 0; j < numCols; j++)

{

rowTotal += matrix[i][j];

}

System.out.println("Sum for row = " + rowTotal);

}

//Requirement #6: traverse each column and sum the values and display the sums

int colTotal = 0;

for (int i = 0; i < numRows; i++)

{

colTotal = 0;

for (int j = 0; j < numCols; j++)

{

colTotal += matrix[j][i];

}

System.out.println("Sum for col = " + colTotal);

}

//Requirement #7: traverse the perimeter and sum the values and display the sum

//sum bottom row matrix

int perTotal = 0;

for (int i = (numRows-1); i < numRows; i++)

{

perTotal = 0;

for (int j = 0; j < numCols; j++)

{

perTotal += matrix[i][j];

}

}

//sum + top row matrix

for (int i = 0; i < numRows - (numRows-1); i++)

{

for (int j = 0; j < numCols; j++)

{

perTotal += matrix[i][j];

}

System.out.println("Sum of perimeter = " + perTotal);

}

// sum + first col middle

for (int i = 1; i < (numRows-1); i++)

{

for (int j = 0; j < numCols - (numCols-1); j++)

{

perTotal += matrix[j][i];

}

System.out.println("Sum = " + perTotal);

}

// sum + last col middle

for (int i = 1; i < (numRows-1); i++)

{

for (int j = (numCols-1); j < numCols; j++)

{

perTotal += matrix[j][i];

}

System.out.println(perTotal);

}

}

如果有人可以帮助我将第一列和最后一列的总和设为2 + 2和8 + 8，我将非常感激。或者，如果您有一种更好的方法来寻找周长。提前致谢！