用1个循环说明2D数组迭代 [英] Explain 2D array iteration with 1 loop

问题描述

有人可以解释为什么此算法可以将2D数组迭代为1D数组吗？换句话说，..有一个循环吗？

Can someone explain why this algorithm works for iterating a 2D array as a 1D array? In other words.. with one loop?

const int Width = 6;
const int Height = 4;

int Array[Width][Height];

for (int I = 0; I < Width * Height; ++I)
{
    Array[I % Width][I / Width] = I; //This line :S
}

for (int I = 0; I < Height; ++I)
{
    for (int J = 0; J < Width; ++J)
    {
        std::cout<<Array[J][I]<<"  ";
    }
    std::cout<<"\n";
}

推荐答案

最简单的方法它的作用是自己插入数字。从0开始，我们将得到：

The easiest way to see how it works is to plug in the numbers yourself. Starting from 0, we'll get:

Array[0 % 6][0 / 6] = Array[0][0]
Array[1 % 6][1 / 6] = Array[1][0]
...
Array[5 % 6][5 / 6] = Array[5][0]
Array[6 % 6][6 / 6] = Array[0][1]
...
Array[11 % 6][11 / 6] = Array[5][1]

等。因为它使用整数除法，所以每次我们通过 Width 值时，它的 i / Width 都会多一个。利用 i％宽度，它将以那个特定的 i /宽度。因为整数除法会被截断，所以直到 i 成为 Width 的下一个倍数之前，这将是相同的。

and so on. Because it uses integer division, each time we go through Width values, it i / Width will be one more. Utilizing i % Width, this will then loop over each value (in this case, 0 to 5) at that specific i / Width. Because integer division truncates, this will be the same until i becomes the next multiple of Width.

这篇关于用1个循环说明2D数组迭代的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！