digitalmars.D.learn - multiSort for sorting AA by value
- Chris (25/25) Apr 21 2015 The following works great. It sorts an AA by value:
- bearophile (23/25) Apr 21 2015 This is a bit shorter and a bit better (writefln is not yet able
The following works great. It sorts an AA by value: 1. by frequency of word 2. by alphabetic order (if two or more words have the same value) import std.stdio : writefln; import std.algorithm.sorting : multiSort; void main() { size_t[string] wcount = [ "hamster":5, "zorro":80, "troll":90, "algorithm":80, "beer":80 ]; struct Word { string word; size_t count; } Word[] sorter; foreach (ref k, ref v; wcount) sorter ~= Word(k, v); assert(wcount.length == sorter.length); sorter.multiSort!("a.count > b.count", "a.word < b.word"); assert(sorter[2].word == "beer"); foreach (ref it; sorter) writefln("%s : %d", it.word, it.count); } I'm happy with it, but maybe there is a more concise implementation?
Apr 21 2015
Chris:I'm happy with it, but maybe there is a more concise implementation?This is a bit shorter and a bit better (writefln is not yet able to format tuples nicely): void main() { import std.stdio: writeln; import std.algorithm.sorting: multiSort; import std.array: array; const size_t[string] wCount = [ "hamster": 5, "zorro": 80, "troll": 90, "algorithm": 80, "beer": 80 ]; auto pairs = wCount.byKeyValue.array; assert(wCount.length == pairs.length); pairs.multiSort!(q{a.value > b.value}, q{a.key < b.key}); assert(pairs[2].key == "beer"); foreach (const ref it; pairs) writeln(it.key, ": ", it.value); } Bye, bearophile
Apr 21 2015
On Tuesday, 21 April 2015 at 11:46:24 UTC, bearophile wrote:Chris:Nice!I'm happy with it, but maybe there is a more concise implementation?This is a bit shorter and a bit better (writefln is not yet able to format tuples nicely): void main() { import std.stdio: writeln; import std.algorithm.sorting: multiSort; import std.array: array; const size_t[string] wCount = [ "hamster": 5, "zorro": 80, "troll": 90, "algorithm": 80, "beer": 80 ]; auto pairs = wCount.byKeyValue.array; assert(wCount.length == pairs.length); pairs.multiSort!(q{a.value > b.value}, q{a.key < b.key}); assert(pairs[2].key == "beer"); foreach (const ref it; pairs) writeln(it.key, ": ", it.value); } Bye, bearophile
Apr 21 2015
Maybe something like bearophile's example should go into the documentation of std.algorithm.sorting.multiSort. It's a common enough thing in programming.
Apr 21 2015