如何构建在Perl使用STDIN一个二维矩阵？ [英] How do I build a 2d matrix using STDIN in Perl?

问题描述

我如何使用STDIN建立一个二维矩阵？

How do I build a 2d matrix using STDIN?

如果我输入像这样一个矩阵：

If I input a matrix like so:

1 2 3
4 5 6
7 5 6

7 8 9
4 5 6
3 3 3

我怎么输入这个并创建两个矩阵出这个？

how do I input this and create two matrices out of this?

下面是我的code到目前为止

Here's my code so far

while (defined ($a=<STDIN>)) {
    chomp ($a);
    push @a,($a);
    }

这仅仅是输入。

我的理解是，我可以每行只添加到堆栈。当矩阵都放在我可以把每一行，通过空间打破创建一个数组。然后，我需要创建一个数组引用，推动此引用到一个数组创建我的矩阵。如何赫克我做到这一点？是否有更简单的方法？我一直在抨击我的头在这3天。我觉得pretty该死的愚蠢现在...

My understanding is I can just add each row to a stack. When the matrices are all put in I can take each line, break by space to create an array. I then need to create an array reference and push this reference into an array to create my matrix. How the heck do I do this? Is there an easier way? I've been bashing my head on this for 3 days now. I feel pretty damn stupid right now...

推荐答案

其他的答案似乎缺少要求从同一输入读取多个矩阵，打破一个空行。有几种不同的方式去了解这一点，包括frobbing $ / ，但这里有一个吸引我的。

The other answers seem to be missing the requirement to read multiple matrices from the same input, breaking on a blank line. There are a few different ways to go about this, including frobbing $/, but here's one that appeals to me.

# Read a matrix from a handle, with columns delimited by whitespace
# and rows delimited by newlines. A matrix ends at a blank line
# (which is consumed) or EOF.
sub read_matrix_from {
  my ($handle) = @_;
  my @out;
  while (<$handle>) {
    last unless /\S/;
    push @out, [ split ];
  }
  return \@out;
}

my @matrices;
push @matrices, read_matrix_from(\*ARGV) until eof();

赛季的最后一部分的味道，当然 - 你可能会使用一个明确打开处理，而不是神奇ARGV，你可能提前知道有多少事情你正在阅读，而不是去EOF等

Season the last part to taste, of course -- you might be using an explicitly opened handle instead of ARGV magic, and you might know in advance how many things you're reading instead of going to EOF, etc.

这篇关于如何构建在Perl使用STDIN一个二维矩阵？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！