Question

目标是获取传入参数的矩阵的转置。

我这样做了，但是没有得到期望的结果：

https://3XXXXXX.io/_oauth/google?close是矩阵，m是结果存储的地方

当我打印它时，只有第一行被换位并成为第一列。

示例：

void transpose(double m[], size_t rows, size_t cols, double r[])
{
    for (size_t i = 0; i < rows; i += 1)
    {
        for (size_t j = 0; j < cols; j += 1)
        {
            r[j * cols + i] = m[i * rows + j];
        }
    }
}

将是：

1 2
3 4

但使用我的代码：

1 3
2 4

给我：

1 2
3 4

Answer 1

此行

r[j * cols + i] = m[i * rows + j];

是错误的。尝试：

r[j * rows + i] = m[i * cols + j];

因为它是给出行之间距离的列数。

Answer 2

正如我在评论中所述以及在4386427的答复中所述，您的映射错误。

演示：

#include <stdio.h>

#define ROW (2)
#define COLUMN (3)

void transpose(double m[], size_t rows, size_t cols, double r[])
{
    for (size_t i = 0; i < rows; i += 1)
    {
        for (size_t j = 0; j < cols; j += 1)
        {
            printf("i = %zu, j = %zu --- Interchanging %lf with %lf\n", i, j, r[j * rows + i], m[i * cols + j]);
            r[j * rows + i] = m[i * cols + j];
        }
    }
}

int main(void)
{
    double m[ROW*COLUMN] = { 1, 2, 3, 4, 5, 6 };
    double n[COLUMN*ROW] = { 7, 8, 9, 10, 11, 12 };

    /*       
     *  m -> 1 2 3
     *       4 5 6
     * 
     *  n -> 7  8
     *       9  10
     *       11 12
     */

    transpose(m, ROW, COLUMN, n);
    printf("\nTranspose of matrix m is (in 1D form):\n");

    for(int i = 0; i < ROW*COLUMN; i++)
    {
        printf("%lf ", n[i]);
    }

    printf("\n");
    return 0;
}

我也初始化了第二个矩阵，以查看哪个数字到达哪里。

输出：

[root@localhost little_programs]# gcc -Wall -std=c99 -o matrix_T matrix_T.c
[root@localhost little_programs]# ./matrix_T
i = 0, j = 0 --- Interchanging 7.000000 with 1.000000
i = 0, j = 1 --- Interchanging 9.000000 with 2.000000
i = 0, j = 2 --- Interchanging 11.000000 with 3.000000
i = 1, j = 0 --- Interchanging 8.000000 with 4.000000
i = 1, j = 1 --- Interchanging 10.000000 with 5.000000
i = 1, j = 2 --- Interchanging 12.000000 with 6.000000

Transpose of matrix m is (in 1D form):
1.000000 4.000000 2.000000 5.000000 3.000000 6.000000

仔细检查循环的每个步骤中发生了什么，您会发现出了什么问题。

C矩阵的转置（行优先级）

2 个答案: