Sum of all integers from 1 to n

Question

I'm honestly surprised that this hasn't been done already. If you can find an existing thread, by all means mark this as a duplicate or let me know.

Input

Your input is in the form of any positive integer greater than or equal to 1.

Output

You must output the sum of all integers between and including 1 and the number input.

Example

 In: 5
     1+2+3+4+5 = 15
Out: 15

OEIS A000217 — Triangular numbers: a(n) = binomial(n+1,2) = n(n+1)/2 = 0 + 1 + 2 + ... + n.

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@FryAmTheEggman Sorry - had a bit of a brain fart there. I see what you mean. — GarethPW, Jul 18, 2017 at 20:45
@Aaron you got ninja'd by Husk, which was just posted with a 1 byte solution — Mayube, Jul 18, 2017 at 21:35

Ginger · Accepted Answer · 2021-12-11 15:51:06Z

1

APOL, 18 bytes

v(0);ⅎ(⧣ ∆(0 ∈));⁰

answered Dec 11, 2021 at 15:51

Ginger

5,4101 gold badge17 silver badges54 bronze badges

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chunes · Accepted Answer · 2022-04-23 13:50:59Z

1

Factor + `math.unicode`, 12 bytes

[ [1,b] Σ ]

Try it online!

Posting this here because the other Factor answer is incorrect.

answered Apr 23, 2022 at 13:50

chunes

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naffetS · Accepted Answer · 2022-06-03 02:55:12Z

1

J-uby, 7 bytes

:+|:sum

Try it online!

answered Jun 3, 2022 at 2:55

naffetS

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Aiden Chow · Accepted Answer · 2022-06-26 03:09:39Z

1

Desmos, 13 bytes

f(n)=.5nn+.5n

Very surprised that there wasn't a Desmos answer here yet.

Try It On Desmos!

answered Jun 26, 2022 at 3:09

Aiden Chow

12.7k1 gold badge14 silver badges53 bronze badges

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Cloudy7 · Accepted Answer · 2022-08-03 03:39:27Z

Mornington Crescent, 1136 bytes

I was surprised not to find an answer here already -- I thought we MC programmers had scoured the simpler challenges pretty clean.

Take Northern Line to Bank
Take Circle Line to Bank
Take District Line to Parsons Green
Take District Line to Bank
Take Circle Line to Hammersmith
Take Circle Line to Notting Hill Gate
Take Circle Line to Notting Hill Gate
Take Circle Line to Aldgate
Take Circle Line to Aldgate
Take Metropolitan Line to Chalfont & Latimer
Take Metropolitan Line to Aldgate
Take Circle Line to Hammersmith
Take Circle Line to Aldgate
Take Circle Line to Aldgate
Take Metropolitan Line to Chalfont & Latimer
Take Metropolitan Line to Aldgate
Take Circle Line to Aldgate
Take Circle Line to Victoria
Take Circle Line to Hammersmith
Take Circle Line to Cannon Street
Take Circle Line to Hammersmith
Take Circle Line to Cannon Street
Take Circle Line to Bank
Take Circle Line to Victoria
Take District Line to Turnham Green
Take District Line to Hammersmith
Take District Line to Turnham Green
Take District Line to Notting Hill Gate
Take Circle Line to Notting Hill Gate
Take District Line to Upminster
Take District Line to Bank
Take District Line to Upminster
Take District Line to Bank
Take Circle Line to Bank
Take Northern Line to Mornington Crescent

Try it online!

Summary of the program:

1. Parse integer from string using Parsons Green and store in Bank
(as far as I know, MC only supports string input)
2. Find bitwise negation of integer using Notting Hill Gate
3. Multiply integer by its bitwise negation using Chalfont & Latimer and store in Victoria
4. Calculate 1 by dividing the input integer by itself using Cannon Street
5. Retrieve stored value from Victoria and bitwise shift right by 1 using Turnham Green
6. Find bitwise negation of result using Notting Hill Gate
7. Add 1 to result using Upminster
8. Output the result via Mornington Crescent

Jo King · Accepted Answer · 2022-09-02 13:47:25Z

1

Prolog (SWI), 18 bytes

N+R:-R is\N* -N/2.

Try it online!

Simple application of the formula

answered Sep 2, 2022 at 13:47

Jo King♦

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UndoneStudios · Accepted Answer · 2022-10-01 04:45:14Z

1

Python 3, 32 19 bytes

lambda z:z*(z+1)//2

-13 bytes because lambdas are small
-6 bytes due to a rereading.
-2 bytes thanks to @oeuf

edited Oct 1, 2022 at 4:45

answered Apr 23, 2022 at 4:51

UndoneStudios

2,0996 silver badges32 bronze badges

\$\begingroup\$ -2 bytes \$\endgroup\$
– oeuf
Apr 23, 2022 at 5:38
\$\begingroup\$ I see. Is the newline counted? \$\endgroup\$
– UndoneStudios
Apr 25, 2022 at 11:12
\$\begingroup\$ @py3programmer yes \$\endgroup\$
– oeuf
Apr 25, 2022 at 13:52
\$\begingroup\$ ok then, so i've updated it \$\endgroup\$
– UndoneStudios
Apr 26, 2022 at 16:07

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The Thonnu · Accepted Answer · 2023-01-29 17:00:21Z

Thunno `+`, 2 bytes

(actually \$ 2 \log_{256}(96) \approx \$ 1.65 bytes but that doesn't show up on the leaderboard)

RS

Attempt This Online!

Thunno, \$ 4 \log_{256}(96) \approx \$ 3.29 bytes

R1+S

Attempt This Online!

or

1+RS

Attempt This Online!

Explanations

RS  # Implicit input
    # The + flag pushes input+1
R   # Push range(0, input+1)
 S  # Sum this list
    # Implicit output

R1+S  # Implicit input
R     # Push range(0, input)
 1+   # Add one to each
   S  # Sum this list
      # Implicit output

1+RS  # Implicit input
1+    # Add one to the input
  R   # Push range(0, input+1)
   S  # Sum this list
      # Implicit output

ATaco · Accepted Answer · 2023-03-23 21:15:52Z

1

TacO, 8 bytes

@+%i
  i

A very simple solution. Iterates from 1 to the first argument, returning the index at each step, then sums the stack. Implicitly output.

@    ; Program Entry
+    ; Sum the result of
 %i  ; Loop from 1 to input
  i  ; Passed value of the loop

Try it online!

answered Mar 23 at 21:15

ATaco

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James Flores · Accepted Answer · 2023-03-24 14:37:34Z

1

PowerShell, 22 bytes

1.."$args"-join'+'|iex

Try it online!

edited Mar 24 at 14:37

answered Mar 23 at 19:40

James Flores

3714 bronze badges

1

\$\begingroup\$ You need to use an argument, hard-coding the input is not a valid approach. Here are some options: 1.."$args"-join'+'|iex or param($a)1..$a-join'+'|iex or 1.."$input"-join'+'|iex \$\endgroup\$
– Julian
Mar 23 at 21:01

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The Thonnu · Accepted Answer · 2023-05-28 14:24:25Z

1

Thunno 2 `S`, 1 byte

Attempt This Online!

Thunno 2, 2 bytes

RS

Attempt This Online!

Pretty simple.

answered May 28 at 14:24

The Thonnu

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The Empty String Photographer · Accepted Answer · 2023-06-23 19:09:43Z

1

Vyxal `Rs`, 0 bytes

Or 2 bytes depending on whether you count the flags here.

Try it Online!

Vyxal has useful flags.

answered Jun 23 at 19:09

The Empty String Photographer

1,7691 gold badge4 silver badges24 bronze badges

\$\begingroup\$ btw: codegolf.stackexchange.com/a/248138 (no need to delete) \$\endgroup\$
– naffetS
Jun 24 at 3:23
\$\begingroup\$ @naffetS I knew there would be a duplicate! \$\endgroup\$
– The Empty String Photographer
Jun 24 at 8:59

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cnamejj · Accepted Answer · 2023-07-01 03:49:20Z

1

Ly, 3 bytes

R&+

Try it online!

A literal interpretation of the contest here...

R    - generate a range of numbers from 0 to "N" (from STDIN)
 &+  - sum the stack
     - print the stack as numeric values by default

answered Jul 1 at 3:49

cnamejj

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macOSisthebestOS · Accepted Answer · 2023-10-01 19:59:08Z

1

Swift, 39 28 bytes

var s={(1...$0).reduce(0,+)}

Fairly self-explanatory.

edited Oct 1 at 19:59

answered Jul 13 at 21:27

macOSisthebestOS

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Jeremy Meadows · Accepted Answer · 2023-10-04 10:30:13Z

1

Uiua, 15 bytes

/+⇡+1parse&sc

Folds an array from 0 to the input number parsed as an integer.

Uiua Pad

edited Oct 4 at 10:30

answered Oct 3 at 10:45

Jeremy Meadows

1712 bronze badges

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roblogic · Accepted Answer · 2023-11-27 05:02:16Z

1

bc, 9 bytes

n*(n+1)/2

Try it online!

Weird how some shell solutions call bc instead of just writing bc code.

answered Nov 27 at 5:02

roblogic

2,73414 silver badges16 bronze badges

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sergiol · Accepted Answer · 2017-07-18 23:39:05Z

0

Tcl, 36 bytes

time {incr s [incr n]} $argv;puts $s

Try it online!

answered Jul 18, 2017 at 23:39

sergiol

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sergiol · Accepted Answer · 2017-07-18 23:58:31Z

0

Tcl, 29 bytes

puts [expr $argv*($argv+1)/2]

Try it online!

answered Jul 18, 2017 at 23:58

sergiol

3,3981 gold badge14 silver badges31 bronze badges

1

\$\begingroup\$ If you've got two Tcl answers, you should probably put them in one answer. \$\endgroup\$
– numbermaniac
Jul 19, 2017 at 0:24
\$\begingroup\$ @numbermaniac I have three. \$\endgroup\$
– sergiol
Jul 19, 2017 at 0:29
6

\$\begingroup\$ Ah. It's probably better to put them all in one answer, then. \$\endgroup\$
– numbermaniac
Jul 19, 2017 at 1:08

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steenbergh · Accepted Answer · 2017-07-19 07:13:55Z

0

QBIC, 10 bytes

?(:+1)/2*a

This prints (input+1) divided by 2 times input. Looping through all numbers from 1 to n is one byte longer:

[:|p=p+a]?p

answered Jul 19, 2017 at 7:13

steenbergh

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Blue · Accepted Answer · 2017-07-19 09:16:40Z

0

Pyke, 2 bytes

Ss

Try it online!

Showing off Pyke's roots in being inspired by Pyth, the function map is exactly the same, only ran as a stack rather than a tree.

S  -  range(1, input+1)
 s - sum(^)

answered Jul 19, 2017 at 9:16

Blue

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Tamoghna Chowdhury · Accepted Answer · 2017-07-19 09:55:11Z

0

Scala, 12 bytes

Gauss sum (12 bytes):

n=>n*(n+1)/2

Naive version (14 bytes):

n=>1.to(n).sum

answered Jul 19, 2017 at 9:55

Tamoghna Chowdhury

3731 silver badge10 bronze badges

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Joshua · Accepted Answer · 2017-07-19 11:21:51Z

0

Clojure, 28 bytes

#(apply + (range 1 (inc %)))

answered Jul 19, 2017 at 11:21

Joshua

2411 silver badge6 bronze badges

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Dylan Meeus · Accepted Answer · 2017-07-19 12:37:27Z

0

Java 8 (39 37 bytes)

n->{System.out.println((n*(n+1))/2);}

saved 2 bytes thanks to @TheLethalCoder. I now realise that I could also omit print statements etc, but there already is a Java answer that I missed, which would end up being pretty much the same thing. Thus I will leave it as this :-)

(Is this the right way of scoring Java? I have no clue if this is valid, I saw it in another answer but this actually omits quite a bit of the code necessary to actually run it..)

try it online

edited Jul 19, 2017 at 12:37

answered Jul 19, 2017 at 12:32

Dylan Meeus

2201 silver badge6 bronze badges

1

\$\begingroup\$ (n) can be just n. You can return from the lambda, I believe, instead of printing. And yes it's fine to compile to a lambda. \$\endgroup\$
– TheLethalCoder
Jul 19, 2017 at 12:34
\$\begingroup\$ Side note: Use four spaces to format the code not back ticks. \$\endgroup\$
– TheLethalCoder
Jul 19, 2017 at 12:34
\$\begingroup\$ @TheLethalCoder thanks! I just found another Java answer to this thread which indeed does it a great deal shorter and does not print ^^ \$\endgroup\$
– Dylan Meeus
Jul 19, 2017 at 12:34

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MattPutnam · Accepted Answer · 2017-07-19 14:50:05Z

0

Clojure, 16 bytes

#(/(*(inc %)%)2)

answered Jul 19, 2017 at 14:50

MattPutnam

5612 silver badges3 bronze badges

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Magic Octopus Urn · Accepted Answer · 2017-07-19 15:14:41Z

0

Groovy, 11 bytes

{it*++it/2}

Try it online!

The input is not modified by rules of Groovy clsures.

edited Jul 19, 2017 at 15:14

answered Jul 19, 2017 at 15:03

Magic Octopus Urn

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ricdesi · Accepted Answer · 2017-07-19 18:30:42Z

0

PHP, 35 34 32 25 bytes

<?=$argv[1]*++$argv[1]/2;

Run from the command line, with the input as a parameter.

edited Jul 19, 2017 at 18:30

answered Jul 19, 2017 at 18:22

ricdesi

4992 silver badges13 bronze badges

\$\begingroup\$ Save 6 bytes with $argn and -F \$\endgroup\$
– Titus
Jul 26, 2017 at 11:34

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Steadybox · Accepted Answer · 2017-07-20 00:05:12Z

0

Fortran 95, 58 bytes

function l(n)
i=1
l=1
do while(i<n)
i=i+1
l=l+i
end do
end

Try it online!

answered Jul 20, 2017 at 0:05

Steadybox

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Clashsoft · Accepted Answer · 2017-07-20 18:52:19Z

0

Dyvil, 12 bytes

n=>n*(n+1)/2

The operator rules force me to use either parentheses or spaces. Uses the Gauss method, and is also a Scala polyglot.

Usage:

let f: int -> int = n=>n*(n+1)/2

print f(5)  // 15
print f(10) // 45

answered Jul 20, 2017 at 18:52

Clashsoft

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Community · Accepted Answer · 2020-06-17 09:04:33Z

0

Swift 3, 60 Bytes

var b=Int.init(readLine()!)!
(1..<b).forEach{b+=$0}
print(b)

Try it online!

edited Jun 17, 2020 at 9:04

CommunityBot

1

answered Jul 21, 2017 at 20:13

Mic1780

1214 bronze badges

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Community · Accepted Answer · 2020-06-17 09:04:33Z

0

Matlab/Octave, 12 bytes

@(n)sum(1:n)

edited Jun 17, 2020 at 9:04

CommunityBot

1

answered Jul 23, 2017 at 18:15

Batman

1114 bronze badges

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Sum of all integers from 1 to n

Input

Output

Example

Leaderboard

222 Answers 222

APOL, 18 bytes

Factor + math.unicode, 12 bytes

J-uby, 7 bytes

Desmos, 13 bytes

Mornington Crescent, 1136 bytes

Prolog (SWI), 18 bytes

Python 3, 32 19 bytes

Thunno +, 2 bytes

Thunno, \$ 4 \log_{256}(96) \approx \$ 3.29 bytes

Explanations

TacO, 8 bytes

PowerShell, 22 bytes

Thunno 2 S, 1 byte

Thunno 2, 2 bytes

Vyxal Rs, 0 bytes

Or 2 bytes depending on whether you count the flags here.

Ly, 3 bytes

Swift, 39 28 bytes

Uiua, 15 bytes

bc, 9 bytes

Tcl, 36 bytes

Tcl, 29 bytes

QBIC, 10 bytes

Pyke, 2 bytes

Scala, 12 bytes

Gauss sum (12 bytes):

Naive version (14 bytes):

Clojure, 28 bytes

Java 8 (39 37 bytes)

Clojure, 16 bytes

Groovy, 11 bytes

PHP, 35 34 32 25 bytes

Fortran 95, 58 bytes

Dyvil, 12 bytes

Swift 3, 60 Bytes

Matlab/Octave, 12 bytes

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