Java，行和列的总和

Question

您好，我正在尝试计算矩阵的每一行和每一列的总和，然后打印最小值的总和。现在我遇到了一个问题。我得到的“smallRows”总和不是矩阵中的最小行。这只是最新的。我该如何改进这个？ 提前致谢!

    {
        int rows = 4;
        int columns = 5;
        int[][] matrix = new int[rows][columns];
        for (int i = 0; i < rows; i++) 
        {
            for (int j = 0; j < columns; j++) 
            {
                matrix[i][j] = new Random().nextInt(9)  + 1;
            }   
        }
        printMatrix(matrix);
        int[] tempRows = new int[columns];
        int[] smallRows = new int[columns];

        for (int i = 0; i < rows; i++) 
        {
            for (int j = 0; j < columns; j++) 
            {
                tempRows[j] = matrix[i][j];
            }

            if(sum(smallRows) == 0)
            {
                smallRows = tempRows;
            }
            if (sum(tempRows) < sum(smallRows)) 
            {
                smallRows = tempRows;
            }
        }
    }
    public static int sum(int[] a)
    {
        int sum = 0;
        for (int i = 0; i < a.length; i++) 
        {
            sum += a[i];    
        }
        return sum;
    }
    public static void printMatrix(int mat[][]) 
    { 
        for (int[] row : mat)
            System.out.println(Arrays.toString(row)); 
    }

Answer 1

以下是如何找出最小值及其索引以及它是来自行还是列

int smallest = Integer.MAX_VALUE;
int indexOfSmallest = -1;
boolean isRow = true;

for (int i = 0; i < rows; i++) { 
    int value = sum(matrix[i]);
    if (value < smallest) {
        smallest = value;
        indexOfSmallest = i;
    } 
}
for (int i = 0; i < columns; i++) { 
    int columnSum = 0;
    for (int j = 0; j < rows; j++) {
        columnSum += matrix[i][j];
    }
    if (columnSum < smallest) {
        smallest = columnSum;
        indexOfSmallest = i;
        isRow = false;
    }
}

之后，您可以打印 indexOfSmallest 和 isRow 指向的最小值的行或列。