我正在一個項目中，我必須讀取文件并將內容輸入2D數組。然后，我必須對每一行，每一列和矩陣的周長求和。到目前為止，除外圍功能外，我一切正常。我正在嘗試為兩個外部列的頂行，底行和中間創建單獨的for循環。

矩陣文件如下所示：

1 2 3 4

2 4 6 8

2 4 6 8

3 2 3 4

因此，周長總計應為42。現在，我可以成功地將第一行和最后一行添加為等于22。但是，當我將列添加到總數中時，我得到32。

這是代碼：

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);

}

}

如果有人可以幫助我將第一列和最后一列的總和設為2 + 2和8 + 8，我將非常感激?；蛘?#xff0c;如果您有一種更好的方法來尋找周長。提前致謝！

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