c - 如何重新排列二维数组

Question

我想将一个数组中的值分配给另一个数组，但使用不同的数组 命令。例如原始数组将是:

1  2  3  4  5  6  7  
8  9  10 11 12 13 14 
15 16 17 18 19 20 21

所需的数组是:

8  11 14 3 6  16 19
9  12 1  4 7  17 20 
10 13 2  5 15 18 21

我该怎么做？在下面的代码中，我将选定的行移动到中心，然后单独分配每个数组。我想不出更好的办法。

int main()
{
int decide, i, j, k;
int save[3][7];
int shuffle[3][7];
int arr[3][7] = {
                {1, 2, 3, 4, 5, 6, 7},
                {8, 9, 10, 11, 12, 13, 14}, 
                {15, 16, 17, 18, 19, 20, 21}
            };

printf("Select a number between 1 and 21\n\n0-GroupA (1 - 7))\n1-GroupB ( 8 - 14)\n2-GroupC (15 - 21)\n\n");

for(k = 0 ; k < 1 ; ++k)
{
    printf("Select which group the number falls into:");
    scanf("%d", &decide);

    for(j = 0 ; j < 7 ; ++j)
    {/*moves selected row to middle row of array*/
        save[0][j] = arr[1][j]; 
        arr[1][j] = arr[decide][j];
        arr[decide][j] = save[0][j];
    }

    /*this is a horrible method*/
    shuffle[0][0] = arr[0][0];
    shuffle[1][0] = arr[0][1];
    shuffle[2][0] = arr[0][2];
    shuffle[0][1] = arr[0][3];
    shuffle[1][1] = arr[0][4];
    shuffle[2][1] = arr[0][5];
    shuffle[0][2] = arr[0][6];
    shuffle[1][2] = arr[1][0];
    shuffle[2][2] = arr[1][1];
    shuffle[0][3] = arr[1][2];
    shuffle[1][3] = arr[1][3];
    shuffle[2][3] = arr[1][4];
    shuffle[0][4] = arr[1][5];
    shuffle[1][4] = arr[1][6];
    shuffle[2][4] = arr[2][0];
    shuffle[0][5] = arr[2][1];
    shuffle[1][5] = arr[2][2];
    shuffle[2][5] = arr[2][3];
    shuffle[0][6] = arr[2][4];
    shuffle[1][6] = arr[2][5];
    shuffle[2][6] = arr[2][6];

}

Answer 1

像这样吗？

#include <stdio.h>

#define ROWS 3
#define COLS 7

int main(void){
    int arr[ROWS][COLS] = {
        {1, 2, 3, 4, 5, 6, 7},
        {8, 9, 10, 11, 12, 13, 14}, 
        {15, 16, 17, 18, 19, 20, 21}
    };
    int result[ROWS][COLS];
    int order[ROWS] = {1, 0, 2};
    int n = sizeof(arr)/sizeof(**arr);//number of elements
    int r = 0, c = 0, i = 0, j = 0;

    while(n--){
        result[r++][c] = arr[order[i]][j++];
        if(r == ROWS){
            r = 0;
            c += 1;
        }
        if(j == COLS){
            j = 0;
            i += 1;
        }
    }
    //check print
    for(r = 0; r < ROWS; ++r){
        for(c = 0; c < COLS; ++c)
            printf("%-2d ", result[r][c]);
        puts("");
    }
}