.cn int 腳本 count erl sin cal 獲取 結果

可以寫循環，也可以用模塊。

百度許久找到一個博客 http://blog.sina.com.cn/s/blog_4a0824490101f1kc.html 詳細介紹了Algorithm::Combinatorics

受此啟發，又找到了 Math::Combinatorics

由於前面的博客介紹了Algorithm::Combinatorics，所以本博客介紹一下Math::Combinatorics

perl 腳本

use Math::Combinatorics;

my @n = qw(a b c);
my $combinat = Math::Combinatorics->new(count => 2,data => [@n]);

print "combinations of 2 from: ".join(" ",@n)."\n";
print "------------------------".("--" x scalar(@n))."\n";
while(my @combo = $combinat->next_combination){
print join(‘ ‘, @combo)."\n";
}
print "\n";

print "display the permutations: ".join(" ",@n)."\n";
print "------------------------".("--" x scalar(@n))."\n";
while(my @permu = $combinat->next_permutation){
print join(‘ ‘, @permu)."\n";
}

結果

combinations of 2 from: a b c
------------------------------
a b
a c
b c

display the permutations: a b c
------------------------------
a b c
a c b
b a c
b c a
c a b
c b a

在N個元素的數組中獲取K個元素的所有組合問題