# Display numbers lacking 2's

Display numbers from one to one-hundred (in increasing order), but number 2 shouldn’t appear anywhere in the sequence. So, for example, the numbers two (2) or twenty-three (23) shouldn't be in the sequence.

Here is an example output, with newlines separating the numbers:

1
3
4
5
6
7
8
9
10
11
13
14
15
16
17
18
19
30
31
33
34
35
36
37
38
39
40
41
43
44
45
46
47
48
49
50
51
53
54
55
56
57
58
59
60
61
63
64
65
66
67
68
69
70
71
73
74
75
76
77
78
79
80
81
83
84
85
86
87
88
89
90
91
93
94
95
96
97
98
99
100

• I assume the winning criteria is code-golf right? – Luis felipe De jesus Munoz Oct 2 '18 at 13:26
• Our site does not work the same way as other sites from the Stack Exchange network. Regarding accepted answers, please take this comment from Jonathan Allan into account. And please add a winning criterion. – Arnauld Oct 2 '18 at 14:08
• Might I suggest using the Sandbox in the future to get feedback on your challenges before posting? – Jo King Oct 2 '18 at 14:15
• @Monolica If the shortest answer wins, you'll need the tag [code-golf]. Here is a list for all available winning criteria tags for future reference. – Kevin Cruijssen Oct 2 '18 at 14:19
• @user202729 Arbitrary restriction is unwelcome, not disallowed. – Jonathan Frech Oct 3 '18 at 1:11

# 05AB1E, 6 bytes

тLʒ2å_


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Explanation

тL       # push [1 ... 100]
ʒ      # filter, keep only elements that
2å_   # does not contain 2


# Taxi, 23992391237017831773 1706 bytes

-8 bytes for realizing that, instead of leaving a certain passenger at Sunny Side Park forever, it's more worth it to throw them off of Riverview Bridge. Ah, what a lovely town this is.

-21 bytes for taking out a comment I stupidly left in.

-587 bytes by simply changing the entire way I went about this (apparently a shorter way is by arithmetic; integer-dividing [17, 27, 37, 47,...] by 9 yields the sequence, but you gotta skip over the 20's yourself.)

-17 bytes for the realization that any quotes-encased string without a space doesn't need quotes after all (thanks Jo King!).

-67 bytes for the realization that linebreaks are optional.

17 is waiting at Starchild Numerology.Go to Starchild Numerology:w 1 l 2 r 1 l 1 l 2 l.Pickup a passenger going to Cyclone.Go to Cyclone:e 1 l 2 r.[B]Pickup a passenger going to Cyclone.Pickup a passenger going to Divide and Conquer.9 is waiting at Starchild Numerology.Go to Starchild Numerology:s 2 l 2 r.Pickup a passenger going to Divide and Conquer.Go to Divide and Conquer:e 1 l 2 r 3 r 2 r 1 r.Pickup a passenger going to Trunkers.Go to Trunkers:e 1 r 3 r 1 l.Pickup a passenger going to The Babelfishery.Go to The Babelfishery:e 1 r 1 r.Pickup a passenger going to Post Office.\n is waiting at Writer's Depot.Go to Writer's Depot:n 5 l 2 l.Pickup a passenger going to Post Office.Go to Post Office:n 1 r 2 r 1 l.Go to Cyclone:s 1 r 1 l 2 r.Pickup a passenger going to Addition Alley.Pickup a passenger going to Equal's Corner.177 is waiting at Starchild Numerology.Go to Starchild Numerology:s 2 l 2 r.Pickup a passenger going to Equal's Corner.Go to Equal's Corner:w 1 l.Switch to plan C if no one is waiting.Pickup a passenger going to Sunny Skies Park.100 is waiting at Starchild Numerology.Switch to plan D.[C]10 is waiting at Starchild Numerology.[D]Go to Starchild Numerology:n 1 r.Pickup a passenger going to Addition Alley.Go to Sunny Skies Park:w 1 r.Go to Addition Alley:n 1 r 1 r 1 r.Pickup a passenger going to Cyclone.Go to Cyclone:n 1 l 1 l.Pickup a passenger going to Cyclone.Pickup a passenger going to Equal's Corner.917 is waiting at Starchild Numerology.Go to Starchild Numerology:s 2 l 2 r.Pickup a passenger going to Equal's Corner.Go to Equal's Corner:w 1 l.Switch to plan E if no one is waiting.Switch to plan F.[E]Go to Go More:n 1 l.Go to Cyclone:w 1 r.Switch to plan B.[F]


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This one isn't winning me any code golf competitions anytime soon, but I decided to try out the esolang Taxi.

Taxi is an esolang in which all programming is done by picking up and dropping off passengers at various stops in the fictional town of Townsburg. Of course, your taxicab will sometimes run out of gas, so you also need to visit gas stations every so often, and pay using the credits you receive as fare (in this case, I only need to stop for gas - at Go More - once per loop iteration!).

I used some tricks that reduce the filesize a bit, such as rephrasing directions like east 1st left, 2nd right as e 1 l 2 r, removing the word the where it is optional, and using the least complicated route towards all of my destinations (not necessarily the shortest path).

I hate this shorter solution more than the one I originally came up with. This solution down here is a more general way of accomplishing the task, which could start and end anywhere you want. Here it is, in its entirety.

# 2245 bytes (way more general)

1 is waiting at Starchild Numerology.Go to Starchild Numerology:w 1 l 2 r 1 l 1 l 2 l.Pickup a passenger going to Cyclone.Go to Cyclone:e 1 l 2 r.[B]Pickup a passenger going to Addition Alley.Pickup a passenger going to The Babelfishery.Go to The Babelfishery:n 2 r 2 r.Pickup a passenger going to Cyclone.Go to Cyclone:n 5 l 2 l.Pickup a passenger going to Chop Suey.Go to Zoom Zoom:n.0 is waiting at Writer's Depot.Go to Writer's Depot:w.Pickup a passenger going to Narrow Path Park.Go to Narrow Path Park:n 3 r 1 l 1 r.Go to Chop Suey:e 1 r 1 l 1 r.[C]Switch to plan E if no one is waiting.Pickup a passenger going to Crime Lab.2 is waiting at Writer's Depot.Go to Writer's Depot:n 1 l 3 l.Pickup a passenger going to Crime Lab.Go to Crime Lab:n 3 r 2 r.Switch to plan D if no one is waiting.Pickup a passenger going to KonKat's.Go to Narrow Path Park:n 5 l.Pickup a passenger going to KonKat's.Go to KonKat's:e 1 r.Pickup a passenger going to Narrow Path Park.Go to Narrow Path Park:n 2 l.Go to Chop Suey:e 1 r 1 l 1 r.Switch to plan C.[D]Go to Chop Suey:n 5 r 1 l.Switch to plan C.[E]Go to Narrow Path Park:n 1 l 1 r 1 l.Pickup a passenger going to Crime Lab.0 is waiting at Writer's Depot.Go to Writer's Depot:w 1 l 1 r 2 l.1 is waiting at Starchild Numerology.Pickup a passenger going to Crime Lab.Go to Crime Lab:n 3 r 2 r.Switch to plan F if no one is waiting.Pickup a passenger going to Riverview Bridge.Go to Cyclone:n 4 l 2 l.Pickup a passenger going to Post Office.Go to Riverview Bridge:n 2 r.\n is waiting at Writer's Depot.Go to Writer's Depot:w 2 l.Pickup a passenger going to Post Office.Go to Post Office:n 1 r 2 r 1 l.Go to Starchild Numerology:s 1 r 1 l 1 l 2 l.Switch to plan G.[F]Go to Cyclone:s 1 r 1 l 2 r.Pickup a passenger going to Riverview Bridge.Go to Riverview Bridge:n 2 r.Go to Starchild Numerology:w 2 l 3 l 2 r.[G]Pickup a passenger going to Addition Alley.Go to Addition Alley:e 1 l 2 r 3 r 1 r.Pickup a passenger going to Magic Eight.101 is waiting at Starchild Numerology.Go to Starchild Numerology:n 1 l 1 l 3 l 2 r.Pickup a passenger going to Magic Eight.Go to Magic Eight:w 1 r 2 r 1 r.Switch to plan H if no one is waiting.Pickup a passenger going to Cyclone.Go to Cyclone:n 1 l 2 r.Switch to plan B.[H]


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And if mega-cheating is allowed, this one is way shorter than either of the last two.

# 456 bytes (totally cheating)

1\n3\n4\n5\n6\n7\n8\n9\n10\n11\n13\n14\n15\n16\n17\n18\n19\n30\n31\n33\n34\n35\n36\n37\n38\n39\n40\n41\n43\n44\n45\n46\n47\n48\n49\n50\n51\n53\n54\n55\n56\n57\n58\n59\n60\n61\n63\n64\n65\n66\n67\n68\n69\n70\n71\n73\n74\n75\n76\n77\n78\n79\n80\n81\n83\n84\n85\n86\n87\n88\n89\n90\n91\n93\n94\n95\n96\n97\n98\n99\n100 is waiting at Writer's Depot.Go to Writer's Depot:w 1 l 2 r 1 l 2 l.Pickup a passenger going to Post Office.Go to Post Office:n 1 r 2 r 1 l.


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• That quotes thing is a helpful one, thanks. However, I disagree with the "don't have to go to the Taxi Garage" thing. Is exiting with an error allowed? I can't find a good set of general rules on this. – JosiahRyanW Oct 5 '18 at 17:11
• Yeah, generally STDERR is ignored. Relevant meta – Jo King Oct 5 '18 at 21:28
• Some of my answers could benefit from that. – JosiahRyanW Oct 5 '18 at 21:56

# Python 2, 39 bytes

k=7
exec"k+=10;print(k>177)*10+k/9;"*81


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Uses arithmetic operations only to generate numbers without 2's.

The value k follows the arithmetic progression 17, 27, 37, 47, ..., which when floor-divided by 9 gives 1,3,4,5,6,7,8,9,10,11,13,14,... which counts up numbers not ending in 2. To skip 20 through 29, outputs are increased by 10 past a certain threshold.

# JavaScript (ES6), 43 bytes

Returns the sequence as a comma-separated string.

f=(n=98)=>n?f(n-=n-27?n%10?1:2:11)+[,n+3]:1


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### Why doing it this way?

We could iterate from $$\1\$$ to $$\100\$$ and test each number with /2/.test(n), which is a rather concise statement. But in this scenario, we'd have to handle empty entries with something like (/2/.test(n)?'':...), which adds a couple more bytes.

For example, this would work for 45 bytes:

f=(n=1)=>n>99?n:(/2/.test(n)?'':[n,,])+f(n+1)


Or this would work for 44 bytes, if a leading comma is acceptable:

f=(n=100)=>n?f(n-1)+(/2/.test(n)?'':[,n]):''


All in all (and until proven otherwise), it turns out to be shorter to skip right away all values of $$\n\$$ that contain a $$\2\$$.

### Commented

f =                 // f is a recursive function taking:
(n = 98) =>         // n = counter, initialized to 98
n ?               // if n is not equal to 0:
f(              //   prepend the result of a recursive call:
n -=          //     update n:
n - 27 ?    //       if n is not equal to 27:
n % 10 ?  //         if n is not a multiple of 10:
1       //           subtract 1 from n
:         //         else:
2       //           subtract 2 from n
:           //       else (n = 27):
11        //         subtract 11 from n (--> 16)
) +             //   end of recursive call
[, n + 3]       //   append a comma, followed by n + 3; notice that this is the value
//   of n *after* it was updated for the recursive call; at the first
//   iteration, we have: n = 98 -> updated to 97 -> n + 3 = 100
:                 // else (n = 0):
1               //   output the first term '1' and stop recursion

• This is so cool! – Emigna Oct 2 '18 at 20:02
• 41 bytes using your trick if we could have a leading comma. – Oliver Oct 3 '18 at 1:22

# R, 19 bytes

grep(2,1:100,inv=T)


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• grep(2,1:100,inv=T) for 19. – J.Doe Oct 2 '18 at 18:34
• Ha - this was what I tried at first but with v=F as well because obviously, I thought to myself, I want the values and not the indices...duh! – ngm Oct 2 '18 at 19:02
• Inverting the regex itself is a byte shorter (in this case). – ngm Oct 2 '18 at 19:23
• Doesn't work, still lets 2s past. You'd need ^[^2]*$ which is, um, not shorter. – J.Doe Oct 2 '18 at 19:24 • What, are we supposed to check our answers now? – ngm Oct 2 '18 at 19:25 # Python 2, 44 bytes print[n for n in range(1,101)if'2'not inn]  Try it online! # Perl 6, 22 bytes put grep {!/2/},1..100  Try it online! There's probably a better way to do the code block, but I couldn't find a regex adverb to invert the match • remove the brackets around the numbers. Otherwise it is fine. – Monolica Oct 2 '18 at 14:01 • @Monolica Fixed – Jo King Oct 2 '18 at 14:05 • @Monolica It seems a little weird that you singled my answer out as not allowed to print as a list, where so many other answers do so. On the other hand, it doesn't cost me any bytes, so whatever – Jo King Oct 3 '18 at 6:33 # PowerShell, 22 16 bytes 1..100-notmatch2  Try it online! -6 bytes thanks to mazzy Generates the range 1 to 100, then pulls out those objects where they do -notmatch the number 2. Running the -notmatch against an array like this acts like a filter on the array. Each item is left on the pipeline, and output is implicit. • ? 1..100-notmatch2 – mazzy Oct 3 '18 at 11:51 • @mazzy Of course, why didn't I think of that? Thanks! – AdmBorkBork Oct 3 '18 at 12:26 # Haskell, 4833 31 bytes Thanks @JonathanFrech for fifteen bytes saved, and @xnor for another two! I missed a big golf and didn't realize main=print$ can be omitted.

filter(all(/='2').show)[1..100]


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Easily extended by changing the 100. Stringifies all the numbers and keeps only those without a '2'.

• See this; the main=print$ is not necessary. Have you tested your code? I do not think that elem'2' is valid syntax. Why map? Simply filter(not.elem '2'.show)[1..100] does the job. – Jonathan Frech Oct 3 '18 at 1:04 • @JonathanFrech Wow, missed that. :/ No clue where that space went! It's there in the TIO... – Khuldraeseth na'Barya Oct 3 '18 at 1:31 • Haskell has notElem for not.elem, but even shorter is all(/='2'). – xnor Oct 3 '18 at 1:47 # Bash + GNU utilities, 16 • 1 byte saved thanks to @Dennis. seq 100|sed /2/d  Try it online! # Japt, 7 bytes Lõs kø2  Lõs kø2 Full Program Lõs Range ["1"..."100"] (numbers are casted to string) k Remove ø2 anything that contains "2"  Try it online! # Java 10, 67 bytes v->{for(int i=0;++i<101;)if(i%10!=2&i/10!=2)System.out.println(i);}  Try it online. Explanation: v->{ // Method with empty unused parameter and no return-type for(int i=0;++i<101;) // Loop i in the range (0, 101) if(i%10!=2 // If i modulo-10 is not 2 &i/10!=2) // And i integer-divided by 10 is not 2 either System.out.println(i);} // Print i with a trailing newline  # Retina, 19 17 bytes  100* .$.>¶
A2


Try it online! Edit: Saved 2 bytes thanks to @ovs, although the last line now includes a newline. Explanation:


100*


Insert 100 characters.

.
$.>¶  Replace each character with the number of characters up to and including that character, plus a newline. A2  Remove all entries that contain a 2. • Does . $.>¶ work for the second stage? – ovs Oct 3 '18 at 13:41
• @ovs I had had something more complicated before and switched to L$ to avoid a leading newline, so I hadn't realised I could switch back, thanks. – Neil Oct 3 '18 at 16:40 # Stax, 6 bytes Ç░τ╒╜h  Run and debug it Unpacked, ungolfed, and commented, it looks like this. AJ 10 squared f output each value in [1 .. n] satisfying the following filter E get array of decimal digits in number 2# count the number of 2s ! logical not  Run this one # Wolfram Language (Mathematica), 42 bytes Print@⌈Range[1,100,10/9]~Drop~{18,26}⌉  Try it online! The arithmetic sequence 1, 19/9, 29/9, 39/9, ... grows at just the right rate that taking the ceiling skips all the numbers ending in 2. Then we get rid of 20 through 29 by Dropping the values at indices 18 through 26. • I don't know if the consensus is that the Print is necessary, but who really cares, anyway. – Misha Lavrov Oct 3 '18 at 1:40 • [...] but who really cares, anyway. -- that's the spirit ... – Jonathan Frech Oct 3 '18 at 1:54 • Do \[LeftCeiling] and \[RightCeiling] really count as a single byte :) – user6014 Oct 5 '18 at 0:41 • @user6014 I'm counting them as the 3 bytes they take up in Unicode, but it's still a bit cheaper than an actual Ceiling command. – Misha Lavrov Oct 5 '18 at 1:37 • @MishaLavrov Sounds fair ! Neat solution. – user6014 Oct 5 '18 at 1:37 ## C (GCC), 62 55 Bytes • 7 Bytes thanks to Jonathan Frech f(n){for(n=0;++n-101;n/10-2&&n%10-2&&printf("%d,",n));} Loops from 1 to 100 and prints the number only if 2 is not in the ones or tens place. Try it online! • – Jonathan Frech Oct 3 '18 at 2:44 • @JonathanFrech thanks that's clever! – Asleepace Oct 3 '18 at 2:48 # Powershell, 19 bytes 1..100-split'.*2.*'  This script show null-value instead 'numbers with 2 inside' and completely solves the task 'number 2 shouldn’t appear anywhere in the sequence'. Output: 1 3 4 5 6 7 8 9 10 11 13 14 15 16 17 18 19 30 31 33 34 35 36 37 38 39 40 41 43 44 45 46 47 48 49 50 51 53 54 55 56 57 58 59 60 61 63 64 65 66 67 68 69 70 71 73 74 75 76 77 78 79 80 81 83 84 85 86 87 88 89 90 91 93 94 95 96 97 98 99 100  ## Powerhsell (output does not contain null-values), 24 bytes 1..100-split'.*2.*'-ne''  # sh + coreutils, 16 chars seq 100|sed /2/d  Generates sequence from 1 to 100 (inclusive) and deletes any lines that have '2' in them. • This code is identical to answer by Digital Trauma. – Ruslan Oct 5 '18 at 21:55 • oh crap, didn't see that one, even though I checked. Should I delete this since mine was posted later? – therealfarfetchd Oct 6 '18 at 7:50 # Z80Golf, 49 48 bytes 00000000: 1630 2e0a 5faf f57b fe02 2818 82ff f182 .0.._..{..(..... 00000010: ff92 3cf5 7dff f1bd 280a fe02 2803 f518 ..<.}...(...(... 00000020: e63c 18fa 7b3c bd20 db3e 31ff 3dff ff76 .<..{<. .>1.=..v  Try it online! Assembly: ld d, 30h ; ascii '0' character ld l, 0Ah ; number 10 and ascii newline tens: ld e,a ; store tens digit xor a ; reset ones digit to 0 push af ; store initial ones digit 0 ones: ld a,e ; get stored tens digit cp 2 jr z,cont ; if tens digit==2(e.g.20-29),skip loop add d rst 38h ; print tens digit pop af ; get stored ones digit add d rst 38h ; print ones digit sub d inc a ; increment ones digit push af ; store ones digit ld a, l rst 38h ; print newline pop af ; get stored ones digit again cp l jr z,cont ; if ones digit==10, break loop cp 2 jr z,inc_again ; if ones digit==2, incr again repeat_loop: push af ; store ones digit again jr ones ; repeat print loop inc_again: inc a jr repeat_loop cont: ld a,e ; get stored tens digit inc a ; increment tens digit cp l jr nz, tens ; if tens place!=10, continue loop ld a,31h rst 38h ; print '1' dec a rst 38h ; print '0' rst 38h ; print '0' halt  Saved one byte with the repeat_loop jump # Python 3, 53 51 50 49 46 bytes ['2'in str(n)or print(n)for n in range(1,101)]  Try it online! Not the strongest language for this task, but I'm new to golfing. Thanks to the commenters for their tips! • Welcome to PPCG! You can get it down to a round 50 by deleting the space before the if. – ElPedro Oct 3 '18 at 18:07 • [print(n)for n in range(1,101)if"2"not in str(n)] works. – JosiahRyanW Oct 4 '18 at 19:22 • Alternatively, based on one of the Python 2 answers: n=17;exec("print((n>177)*10+n//9);n+=10;"*81) – JosiahRyanW Oct 4 '18 at 19:24 • @JosiahRyanW I wasn't aware of the implicit print, thanks! – Gigaflop Oct 4 '18 at 19:29 • '2'in str(n)or print(n) is shorter than a comprehension guard. – Jonathan Frech Oct 9 '18 at 3:01 # Tcl, 44 bytes time {if ![regexp 2 [incr i]] {puts$i}} 100


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# Tcl, 47 bytes

time {if [incr i]%10!=2&$i/10!=2 {puts$i}} 100


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# Tcl, 50 bytes

time {if {2 ni [split [incr i] ""]} {puts $i}} 100  Try it online! • # Tcl, 49 bytes time {if [string f 2 [incr i]]==-1 {puts$i}} 100Failed outgolf! – sergiol Oct 3 '18 at 9:45
• You could replace your test with a regexp: ![regexp 2 [incr i]] for -3 bytes – david Nov 23 '18 at 5:59
• @david How was it possible I didn't come with the solution suggested by you of using regular expressions? Thanks. – sergiol Nov 23 '18 at 10:20

# Kotlin, 32 bytes

{(1..100).filter{'2' !in ""+it}}


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# Bash, 31 bytes

printf %d\\n {1..100}|grep -v 2


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Thanks to Digital Trauma for short loop.

• Welcome to PPCG! How about echo $i instead of the printf? Or even better printf %d\\n {1..100}|grep -v 2? – Digital Trauma Oct 3 '18 at 3:12 • yeah right. i ll update my answer. – ketone Oct 3 '18 at 3:14 • i am learning actually i don't know that much btw thanks. – ketone Oct 3 '18 at 3:16 • Just beats my echo {1..100}|tr ' ' \\n|grep -v 2 – Mark Perryman Oct 3 '18 at 8:35 • -1 byte if you use sed /2/d instead of grep -v 2. – Ruslan Oct 5 '18 at 21:58 # ORK, 1092 bytes There is such a thing as a t A t can w a number A t can d a number A t has a t which is a number When a t is to w a number: I have a mathematician called M M's first operand is the number M's second operand is 1 M is to add The number is M's result My t is 0 I have a number called n n is the number I am to d n M's first operand is my t M's second operand is 1 M is to compare I have a scribe called W If M says it's less then W is to write the number If M says it's less then W is to write " " M's first operand is the number M's second operand is 100 M is to compare If M says it's less then I am to loop When a t is to d a number: I have a mathematician called M M's first operand is the number M's second operand is 10 M is to modulo I have a mathematician called N N's first operand is M's result N's second operand is 2 N is to compare If N says it's equal then my t is 1 M is to divide The number is M's result M's first operand is the number M's second operand is 0 M is to compare If M says it's greater then I am to loop When this program starts: I have a t called T T is to w 0  Try it online! Objects R Kool. Output is a space-delimited list of numbers. This translates (approximately) to the following pseudocode: class t { int t; void w(number) { label T_W; mathematician M; M.first_operand = number; M.second_operand = 1; M.add(); number = M.result; t = 0; int n = number; d(n); M.first_operand = t; M.second_operand = 1; M.compare(); scribe W; if M.its_less { W.write(number); } if M.its_less { W.write(" "); } M.first_operand = number; M.second_operand = 100; M.compare(); if M.its_less { goto T_W; } } void d(number) { label T_D; mathematician M; M.first_operand = number; M.second_operand = 10; M.modulo(); mathematician N; N.first_operand = M.result; N.second_operand = 2; N.compare(); if N.its_equal { t = 1; } M.divide(); number = M.result; M.first_operand = number; M.second_operand = 0; M.compare(); if M.its_greater { goto T_D; } } } void main() { t T; T.w(0); }  As you can see, everything is done using objects, including basic math and IO functions (through the built-in mathematician and scribe classes). Only whole functions can loop, which explains the need for an object with two functions to do the work. ## Perl (18+2 chars) perl -E 'map/2/||say,1..100'  # MathGolf, 7 6 bytes ♀╒Ç{2╧  Try it online! ## Explanation ♀╒ Push 100 and convert to 1-based range ([1,2,...,100]) Č{ Inverse filter by block 2╧ Does the number contain 2?  # C (clang), 56 bytes f(i){for(i=0;i++<100;i%10^2&&i/10^2&&printf("%d\n",i));}  Try it online! # PHP 7.1, 40 bytes while($i++<100)strstr($i,50)||print$i._;


prints numbers separated by underscores. Run with -nr or try it online.

• Nice use of PHP's wacky behavior to separate the numbers, lol – Roberto Maldonado Oct 3 '18 at 5:19
• The preg_filter() based one is interesting. (I never used that function. 🤫) That one would be shorter with preg_grep(): <?=join(_,preg_grep("/2/",range(1,100),1));. – manatwork Oct 3 '18 at 7:50

# Red, 44 bytes

repeat n 100[unless find form n"2"[print n]]


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Uses unless instead of if not, because why not? :)

# brainfuck, 176 bytes

---------[[-<]-[>]>[>]-[-<]<++]-[>-<+++++++++]>--[>[->]<[<<<]>>[->]>-]<<,<-[-<]>[>]<[.[->+<]++++++++++.,<]>>[>]>>->-<<<<[>>>[<<[<]<.>>[>]>.[-<+>]++++++++++.,>]<<[<]<,<]>>>>.<..


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Shorter is definitely possible. This generates the numbers 1,3,4,5,6,7,8,9 and 0,1,3,4,5,6,7,8,9. First it outputs each number in the first list, then it outputs every combination of the first and second list, then finally prints just 100.

### Explanation:

---------   Push minus 9
[           Repeat 9 times
[-<]-[>]    Add the negative of the number to the first list
>[>]-[-<]<  Add the negative of the number to the second list
++          Increment the counter
]
Tape: 255 254 253 252 251 250 249 248 247 0' 0 246 247 248 249 250 251 252 253 254
-[>-<+++++++++]>--  Push 197
Tape: 255 254 253 252 251 250 249 248 247 0 197' 246 247 248 249 250 251 252 253 254
[
>[->]<    Subtract 197 from every element in both lists to convert to digits
[<<<]>>
[->]>-
]
Tape: 58 57 56 55 54 53 52 51 49 0' 49 50 51 52 53 54 55 56 57
<<,<-[-<]>[>]<  Remove the 0 and the 2 from the first list
Tape: 58 57 56 55 54 53 52 51 0 0 0' 49 50 51 52 53 54 55 56 57
[  Loop over the first list
.[->+<]        Print digit
++++++++++.,<  Print a newline
]
>>[>]>>->-   Remove the 2 from the second list
<<<<
[  Loop over first list
>>>
[  Loop over second list
<<[<]<.        Print first digit
>>[>]>.        Print second digit
[-<+>]         Move second digit over one
++++++++++.,>  Print a newline
]
<<[<]<,<  Remove the digit from the first list and move to the next
]
>>>>.<..  Print 100 using the second list
`