我正在研究一个项目,我必须读取一个文件并将内容输入到二维数组中。然后我必须对矩阵的每一行,每一列和周长进行求和。除了外围,我拥有的一切工作至今。我正尝试为两个外侧列的顶行,底行和中间创建单独的for循环。找到二维数组的总和java
矩阵文件看起来像这样:
1 2 3 4
2 4 6 8
2 4 6 8
3 2 3 4
因此周边加起来应该42 现在我可以成功添加了第一排和最后一排等于22.然而,当我添加列于总,我得到32
下面是代码:
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);
}
}
我会hugeeeeeely感激,如果有人可以帮助我在第一列和最后一列的中间(应该是2 + 2和8 + 8)。或者如果你有一个更好的方式找到周边。提前致谢!
你让一切都太复杂了。您不需要两个for循环来计算一个行/列。实际上,每次for循环只执行一次迭代。因此,如果您知道for循环只执行一次迭代,请修正该值并且不要用于循环 – Martinsos 2013-03-26 13:49:59