On Friday, 28 June 2013 at 16:25:25 UTC, Brad Anderson wrote:
On Friday, 28 June 2013 at 16:04:35 UTC, Benjamin Thaut wrote:
I'm currently making a few tests with std.algorithm,
std.range, etc
I have a arry of words. Is it possible to count how often each
word is contained in the array and then sort the array by the
count of the individual words by chaining ranges? (e.g.
without using a foreach loop + hashmap)?
If you don't mind sorting twice:
words.sort()
.group()
.array()
.sort!((a, b)=> a[1] > b[1])
.map!(a => a[0])
.copy(words);
You could also do it with a hashmap to keep the count.
Like so:
size_t[string] dic;
words.map!((w) { ++dic[w.idup]; return w; })
.array // eager (so dic is filled first), sortable
.sort!((a, b) { bool less = dic[a] > dic[b]; return less
|| less && a < b; })
.uniq
.copy(words);
It's a bit ugly and abuses side effects with the hash map. The
order will differ from the other program when words have
identical counts.
