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！
