c - 如何更改二维数组中的位置

Question

例如，假设有宽度和高度，6 和 4 分别来自用户输入，并且存储在 2D 数组中的输入(也来自用户输入)为:

0 1 2 2 1 0
1 0 0 0 0 1
1 0 0 0 0 1
0 1 1 1 1 0

有没有办法翻转x轴和y轴？我想做的是改变

0 1 2 2 1 0
1 0 0 0 0 1
1 0 0 0 0 1
0 1 1 1 1 0

进入

0 1 1 0
1 0 0 1
2 0 0 1
2 0 0 1
1 0 0 1
0 1 1 0

下面的代码，

scanf("%d %d", &width, &height);
int board[height][width];

for(i = 0; i < height; i++)
{
    for(j = 0; j < width; j++)
    {
        scanf("%d", &input);
        board[i][j] = input;
    }
}

通过做

for(i = 0; i < width; i++)
{

    for(j = 0; j < height; j++)
    {
        printf("%d", board[j][i]);
    }
    printf("\n");
}

，这打印出了我期望的输出，但它实际上并没有改变它的位置...我无法更改第一个编码部分，因为我已经用它来做其他工作了。有没有办法通过添加其他方法或新板来解决问题？

有人可以帮我吗？如果有人帮助我，我将非常感激!谢谢

Answer 1

只需声明第二个数组，其中指定的行数等于width，列数等于height，并将值从源数组复制到第二个数组.

例如

#include <stdio.h>

int main(void) 
{
    size_t height, width;

    printf( "Enter the height and the width of the array: " );

    scanf( "%zu %zu", &height, &width );

    int a[height][width];

    puts( "Enter values for elements of the array" );

    for ( size_t i = 0; i < height; i++ )
    {
        printf( "%zu row: ", i + 1 );
        for ( size_t j = 0; j < width; j++ ) scanf( "%d", &a[i][j] );
    }

    int b[width][height];

    for ( size_t i = 0; i < height; i++ )
    {
        for ( size_t j = 0; j < width; j++ ) b[j][i] = a[i][j];
    }

    puts( "\nSource array is" );

    for ( size_t i = 0; i < height; i++ )
    {
        for ( size_t j = 0; j < width; j++ ) printf( "%d ", a[i][j] );
        putchar( '\n' );
    }

    puts( "\nReversed array is" );

    for ( size_t i = 0; i < width; i++ )
    {
        for ( size_t j = 0; j < height; j++ ) printf( "%d ", b[i][j] );
        putchar( '\n' );
    }

    return 0;
}

程序输出可能如下所示

Enter the height and the width of the array: 4 6
Enter values for elements of the array
1 row: 0 1 2 2 1 0 
2 row: 1 0 0 0 0 1
3 row: 1 0 0 0 0 1 
4 row: 0 1 1 1 1 0 

Source array is
0 1 2 2 1 0 
1 0 0 0 0 1 
1 0 0 0 0 1 
0 1 1 1 1 0 

Reversed array is
0 1 1 0 
1 0 0 1 
2 0 0 1 
2 0 0 1 
1 0 0 1 
0 1 1 0 

另一种方法是动态分配第一数组和辅助数组。例如

#include <stdio.h>
#include <stdlib.h>

int main(void) 
{
    size_t height, width;

    printf( "Enter the height and the width of the array: " );

    scanf( "%zu %zu", &height, &width );

    int **a = malloc( height * sizeof( int * ) );

    for ( size_t i = 0; i < height; i++ ) a[i] = malloc( width * sizeof( int ) );

    puts( "Enter values for elements of the array" );

    for ( size_t i = 0; i < height; i++ )
    {
        printf( "%zu row: ", i + 1 );
        for ( size_t j = 0; j < width; j++ ) scanf( "%d", &a[i][j] );
    }

    int **b = malloc( width * sizeof( int * ) );
    for ( size_t i = 0; i < width; i++ ) b[i] = malloc( height * sizeof( int ) );

    for ( size_t i = 0; i < height; i++ )
    {
        for ( size_t j = 0; j < width; j++ ) b[j][i] = a[i][j];
    }

    puts( "\nSource array is" );

    for ( size_t i = 0; i < height; i++ )
    {
        for ( size_t j = 0; j < width; j++ ) printf( "%d ", a[i][j] );
        putchar( '\n' );
    }

    for ( size_t i = 0; i < height; i++ ) free( a[i] );
    free( a );

    a = b;

    puts( "\nReversed array is" );

    for ( size_t i = 0; i < width; i++ )
    {
        for ( size_t j = 0; j < height; j++ ) printf( "%d ", a[i][j] );
        putchar( '\n' );
    }

    for ( size_t i = 0; i < width; i++ ) free( a[i] );
    free( a );

    return 0;
}