从9x9矩阵中抽取中间菱形区域打印 - perl

起因：源自于c的练习题，打印diamond，因为perl不需编译，方便调试，故先用perl实现一下

关键：没有想到好的思路，只能借助于上一篇打印上下三角矩阵的方法，把菱形拆成上下左右4个三角矩阵区域来实现。

 1 #!/usr/bin/perl -w
 2 use strict;
 3 ## ------------------------------- diamond -----------------------------------------
 4 ## upper peak
 5 for my $row (reverse(1..9))
 6 {
 7     ## upper left
 8     for my $col(1..9)
 9     {
10         if($col >= $row)
11         {
12             print "* ";
13         }
14         else
15         {
16             print "  ";
17         }
18     }
19 
20     ## upper right
21     for my $col(reverse(1..9))
22     {
23         if($col > $row)
24         {
25             print "* ";
26         }
27         else
28         {
29             print "  ";
30         }
31     }
32     print "\n";
33 }
34 
35 ## lower peak
36 for my $row (2..9)
37 {
38     print "  ";
39     ## lower left
40     for my $col(2..9)
41     {
42         if($col >= $row)
43         {
44             print "* ";
45         }
46         else
47         {
48             print "  ";
49         }
50     }
51 
52     ## lower right
53     for my $col(reverse(2..9))
54     {
55         if($col > $row)
56         {
57             print "* ";
58         }
59         else
60         {
61             print "  ";
62         }
63     }
64     print "\n";
65 }

输出：

posted on 2016-07-17 12:24 wangshaobin07 阅读(297) 评论(0) 收藏举报