如何修复这个2-D阵列？ [英] How do I fix this 2-D array?

问题描述

public int [] [] flipPhoto（int [] [] picture）

{

int flip [] [] = picture;

int k = 0;

for（int i = 0; i< picture.length; i ++）

{

for（int j = picture [i] .length -1; j> = 0; j--）

{

flip [i] [k] = picture [i] [j];

k ++;

}

k = 0;

}



返回翻转;

}



我的尝试：



我试过改变i和k变量，但是没有用。

这就是我要打印的内容：

[[200,100,200]，[100,200,100]，[100,250,150]]



打印出来的是：

[[200,100,200]，[100,200,100]，[100， 250,100]]



如此接近我不知道该怎么做。

public int[][] flipPhoto(int[][] picture)
{
int flip[][] = picture;
int k = 0;
for (int i = 0; i < picture.length; i++)
{
for (int j = picture[i].length -1 ; j >= 0; j--)
{
flip[i][k]=picture[i][j];
k++;
}
k = 0;
}

return flip;
}

What I have tried:

I have tried inter changing the i and k variables but that doesnt work.
This is what i want to print out:
[[200, 100, 200], [100, 200, 100], [100, 250, 150]]

This is what prints out:
[[200, 100, 200], [100, 200, 100], [100, 250, 100]]

so close i dont know what to do.

推荐答案

你真的意识到这段代码：

You do realize that this code:

int flip[][] = picture;

复制对原始数组的引用，而不是复制数组本身？

所以当你这样做时：

Copies a reference to teh original array, not copies the array itself?
So when you do this:

flip[i][k]=picture[i][j];

它修改了翻转和图片 - 图片[i] [k]中的元素也被覆盖。

试试这个：

It modifies flip and picture - the element at picture[i][k] is also overwritten.
Try this:

int[] ar = new int[3];
    ar[0] = 0;
    ar[1] = 1;
    ar[2] = 2;
    int[] ar2 = ar;
    ar2[1] = 7;
    System.out.print(ar[0]);
    System.out.print(ar[1]);
    System.out.print(ar[2]);

你会得到072，因为ar2是引用，而不是元素的副本。

And you will get "072" because ar2 is a copy of the reference, not a copy of the elements.

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