# Can you explain code **URL:** \ **Category:** Ruby\ **Created:** [January 8, 2010, 5:30pm UTC](https://www.ruby-forum.com/t/can-you-explain-code/181279 "2010-01-08T17:30:05Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![aashishkiran](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/4da419/32.png) [@aashishkiran](https://www.ruby-forum.com/u/aashishkiran)\ **Post date:** [January 8, 2010, 5:30pm UTC](https://www.ruby-forum.com/t/can-you-explain-code/181279/1 "2010-01-08T17:30:05Z")
---------------------ruby code-------------------- after running ruby code in below output at first occurrence of “sssssssssssssssssssssss” can anyone explain how “nearValues” is updating $hash2={“value1”=\>[“value2”, “value3”, “value6”], “value2”=\>[“value1”, “value3”, “value6”], “value3”=\>[“value1”, “value2”, “value6”], “value4”=\>[“value5”, “value6”], “value5”=\>[“value4”, “value6”], “value6”=\>[“value4”, “value5”, “value1”, “value2”, “value3”]} $subgraphs = [] def get\_subgraphs(setGroup, nearValues, checkedValues) p “aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa” p “setGroup” p setGroup p “nearValues” p nearValues p “checkedValues” p checkedValues if nearValues.empty? && checkedValues.empty? $subgraphs \<\< setGroup.sort.join(", ") if setGroup.size \> 2 else possible\_pivots = nearValues + checkedValues p “possible\_pivots” p possible\_pivots ``` pivot = possible_pivots.inject(nil) do |best, p| best.nil? || $hash2[p].size > best.size ? best = p : best end p " pivot " p pivot nearValues.size.times do |i| n = nearValues[i] next if $hash2[n].include?(pivot) nearValues[i] = nil p "i" p i p "checkedValues" p checkedValues p "nearValues.compact & $hash2[n]" p nearValues.compact & $hash2[n] p " checkedValues & $hash2[n]" p checkedValues & $hash2[n] get_subgraphs(setGroup + [n], nearValues.compact & $hash2[n], ``` checkedValues & $hash2[n]) p “sssssssssssssssssssssss” ``` checkedValues << n p "checkedValues" p checkedValues p "nearValues" p nearValues end ``` end end p “$hash2 =” p $hash2 p “$hash2.keys =” p $hash2.keys get\_subgraphs([], $hash2.keys, []) p “$subgraphs =” p $subgraphs puts $subgraphs.sort.join("\n") \<\< “\n” ----------------------end-------------------- ---------------- output is as follows --------------------------- Hello World “$hash2 =” {“value1”=\>[“value2”, “value3”, “value6”], “value2”=\>[“value1”, “value3”, “value6”], “value3”=\>[“value1”, “value2”, “value6”], “value4”=\>[“value5”, “value6”], “value5”=\>[“value4”, “value6”], “value6”=\>[“value4”, “value5”, “value1”, “value2”, “value3”]} “$hash2.keys =” [“value1”, “value2”, “value3”, “value4”, “value5”, “value6”] “aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa” “setGroup” [] “nearValues” [“value1”, “value2”, “value3”, “value4”, “value5”, “value6”] “checkedValues” [] “possible\_pivots” [“value1”, “value2”, “value3”, “value4”, “value5”, “value6”] " pivot " “value1” “i” 0 “checkedValues” [] “nearValues.compact & $hash2[n]” [“value2”, “value3”, “value6”] " checkedValues & $hash2[n]" [] “aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa” “setGroup” [“value1”] “nearValues” [“value2”, “value3”, “value6”] “checkedValues” [] “possible\_pivots” [“value2”, “value3”, “value6”] " pivot " “value2” “i” 0 “checkedValues” [] “nearValues.compact & $hash2[n]” [“value3”, “value6”] " checkedValues & $hash2[n]" [] “aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa” “setGroup” [“value1”, “value2”] “nearValues” [“value3”, “value6”] “checkedValues” [] “possible\_pivots” [“value3”, “value6”] " pivot " “value3” “i” 0 “checkedValues” [] “nearValues.compact & $hash2[n]” [“value6”] " checkedValues & $hash2[n]" [] “aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa” “setGroup” [“value1”, “value2”, “value3”] “nearValues” [“value6”] “checkedValues” [] “possible\_pivots” [“value6”] " pivot " “value6” “i” 0 “checkedValues” [] “nearValues.compact & $hash2[n]” [] " checkedValues & $hash2[n]" [] “aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa” “setGroup” [“value1”, “value2”, “value3”, “value6”] “nearValues” [] “checkedValues” [] “sssssssssssssssssssssss” “checkedValues” [“value6”] “nearValues” [nil] “sssssssssssssssssssssss” “checkedValues” [“value3”] “nearValues” [nil, “value6”] “sssssssssssssssssssssss” “checkedValues” [“value2”] “nearValues” [nil, “value3”, “value6”] “sssssssssssssssssssssss” “checkedValues” [“value1”] “nearValues” [nil, “value2”, “value3”, “value4”, “value5”, “value6”] “i” 3 “checkedValues” [“value1”] “nearValues.compact & $hash2[n]” [“value5”, “value6”] " checkedValues & $hash2[n]" [] “aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa” “setGroup” [“value4”] “nearValues” [“value5”, “value6”] “checkedValues” [] “possible\_pivots” [“value5”, “value6”] " pivot " “value5” “i” 0 “checkedValues” [] “nearValues.compact & $hash2[n]” [“value6”] " checkedValues & $hash2[n]" [] “aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa” “setGroup” [“value4”, “value5”] “nearValues” [“value6”] “checkedValues” [] “possible\_pivots” [“value6”] " pivot " “value6” “i” 0 “checkedValues” [] “nearValues.compact & $hash2[n]” [] " checkedValues & $hash2[n]" [] “aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa” “setGroup” [“value4”, “value5”, “value6”] “nearValues” [] “checkedValues” [] “sssssssssssssssssssssss” “checkedValues” [“value6”] “nearValues” [nil] “sssssssssssssssssssssss” “checkedValues” [“value5”] “nearValues” [nil, “value6”] “sssssssssssssssssssssss” “checkedValues” [“value1”, “value4”] “nearValues” [nil, “value2”, “value3”, nil, “value5”, “value6”] “i” 4 “checkedValues” [“value1”, “value4”] “nearValues.compact & $hash2[n]” [“value6”] " checkedValues & $hash2[n]" [“value4”] “aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa” “setGroup” [“value5”] “nearValues” [“value6”] “checkedValues” [“value4”] “possible\_pivots” [“value6”, “value4”] " pivot " “value6” “i” 0 “checkedValues” [“value4”] “nearValues.compact & $hash2[n]” [] " checkedValues & $hash2[n]" [“value4”] “aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa” “setGroup” [“value5”, “value6”] “nearValues” [] “checkedValues” [“value4”] “possible\_pivots” [“value4”] " pivot " “value4” “sssssssssssssssssssssss” “checkedValues” [“value4”, “value6”] “nearValues” [nil] “sssssssssssssssssssssss” “checkedValues” [“value1”, “value4”, “value5”] “nearValues” [nil, “value2”, “value3”, nil, nil, “value6”] “$subgraphs =” [“value1, value2, value3, value6”, “value4, value5, value6”] value1, value2, value3, value6 value4, value5, value6 ---
**Author:** ![aashishkiran](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/4da419/32.png) [@aashishkiran](https://www.ruby-forum.com/u/aashishkiran)\ **Post date:** [January 8, 2010, 6:08pm UTC](https://www.ruby-forum.com/t/can-you-explain-code/181279/2 "2010-01-08T18:08:01Z")
Aashish K. wrote: > ---------------------ruby code-------------------- > > after running ruby code > > in below output at first occurrence of > > “sssssssssssssssssssssss” > > can anyone explain how “nearValues” is updating (skip long useless code and output) Well, your code says this: ``` nearValues.size.times do |i| n = nearValues[i] next if $hash2[n].include?(pivot) nearValues[i] = nil ``` That means, er. … If the pivot is in $hash2[n], whatever that means, then go to the next number. Otherwise, if the pivot is not in $hash2[n], nearValues[i] is set to nil. This, incidentally, is absolutely terrible Ruby, and I want to inflict a lot of pain to the person who wrote it. ---
**Author:** ![aashishkiran](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/4da419/32.png) [@aashishkiran](https://www.ruby-forum.com/u/aashishkiran)\ **Post date:** [January 8, 2010, 7:15pm UTC](https://www.ruby-forum.com/t/can-you-explain-code/181279/3 "2010-01-08T19:15:54Z")
Aldric G. wrote: > Aashish K. wrote: > > > ---------------------ruby code-------------------- > > > > after running ruby code > > > > in below output at first occurrence of > > > > “sssssssssssssssssssssss” > > > > can anyone explain how “nearValues” is updating > > (skip long useless code and output) > > Well, your code says this: > > ``` > nearValues.size.times do |i| > n = nearValues[i] > next if $hash2[n].include?(pivot) > nearValues[i] = nil > > ``` > > That means, er. … If the pivot is in $hash2[n], whatever that means, > then go to the next number. Otherwise, if the pivot is not in $hash2[n], > nearValues[i] is set to nil. > This, incidentally, is absolutely terrible Ruby, and I want to inflict a > lot of pain to the person who wrote it. thank you for reply can you please explain how nearValues is adding values “sssssssssssssssssssssss” “checkedValues” [“value6”] “nearValues” [nil] “sssssssssssssssssssssss” “checkedValues” [“value3”] “nearValues” [nil, “value6”] “sssssssssssssssssssssss” “checkedValues” [“value2”] “nearValues” [nil, “value3”, “value6”] “sssssssssssssssssssssss” “checkedValues” [“value1”] “nearValues” [nil, “value2”, “value3”, “value4”, “value5”, “value6”] “i” 3 ---
**Author:** ![aashishkiran](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/4da419/32.png) [@aashishkiran](https://www.ruby-forum.com/u/aashishkiran)\ **Post date:** [January 8, 2010, 8:42pm UTC](https://www.ruby-forum.com/t/can-you-explain-code/181279/4 "2010-01-08T20:42:22Z")
Aashish K. wrote: > Aldric G. wrote: > > > Aashish K. wrote: > > > > > can anyone explain how “nearValues” is updating > > > > (skip long useless code and output) > > > > Well, your code says this: > > > > ``` > > nearValues.size.times do |i| > > n = nearValues[i] > > next if $hash2[n].include?(pivot) > > nearValues[i] = nil > > > > ``` > > > > That means, er. … If the pivot is in $hash2[n], whatever that means, > > then go to the next number. Otherwise, if the pivot is not in $hash2[n], > > nearValues[i] is set to nil. > > This, incidentally, is absolutely terrible Ruby, and I want to inflict a > > lot of pain to the person who wrote it. > > thank you for reply > can you please explain how nearValues is adding values No, because that’s not in the code supplied. nearValues is passed to this method. The code is ugly but very readable. Go over it a few times and it will make sense. Hints: - “p” means “puts” and stands for ‘send to the screen’ (basically) - Unknown methods can be looked up here: [RDoc Documentation](http://ruby-doc.org/core/)