Given a string, calculate the number of the column it corresponds to

Question

In Excel, the columns range from A-Z, AA,AB,AZ,BA,..,BZ and so on. They actually each stand for numbers, but rather are encoded as alphabet strings.

In this challenge, you will be given a string of alphabets, and you must calculate the column it corresponds to.

Some tests:

'A' returns 1 (meaning that it is the first column)

'B' returns 2

'Z' returns 26

'AA' returns 27

'AB' returns 28

'AZ' returns 52

'ZZ' returns 702

'AAA' returns 703

You can assume that capital letters will be given only.

Shortest bytes win.

Good luck!

Answer 1

Perl 6, 17 bytes

{:26[.ords X-64]}

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Anonymous code block that subtracts 64 from each byte value and converts from base 26 with Z overflowing to the next column.

Answer 2

Google Sheets, 21 bytes

(formula evaluates to the result, takes input from cell A1)

=column(indirect(A1&2

Answer 3

R, 48 43 bytes

-5 bytes thanks to @Giuseppe, using the same logic, but as a program that eliminates the nchar call.

for(i in utf8ToInt(scan(,"")))F=F*26+i-64;F

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Answer 4

Java (JDK), 39 bytes

s->s.chars().reduce(0,(a,b)->a*26+b%32)

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Answer 5

Python 2, 52 45 bytes

t=0
for c in input():t=26*t+ord(c)%64
print t

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Answer 6

PHP, 41 38 bytes

-3 thanks to Jo King.

for($c=A;$c!=$argn;$i++)$c++;echo$i+1;

run as pipe with -nr

unary output, 34 bytes:

1<?for($c=A;$c!=$argn;$c++)echo 1;

requires PHP 7.1. save to file, run as pipe with -nF.

Answer 7

05AB1E, 6 bytes

Çžx-₂β

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Answer 8

Haskell, 38 34 31 bytes

foldl(\o->(o*26-64+).fromEnum)0

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Answer 9

Jelly, 7 bytes

ØAiⱮḅ26

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Answer 10

C (gcc), 46, 43 bytes

a;f(int*s){for(a=0;*s;)a=*s++%64+a*26;s=a;}

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Degolf

a; f(int*s)
{  for(a=0;*s;) // Loop through s, which is a null-terminated string.
       a=*s++%64 + a*26; // Multiply accumulated value by 26, and add current char modulo 64 to it.
   s=a;} // Return the accumulated value.

Answer 11

APL(NARS), 11 chars, 22 bytes

{+/26⊥⎕A⍳⍵}

test

  f←{+/26⊥⎕A⍳⍵} 
  f¨'A' 'AA' 'AAA'
1 27 703 
  f¨'AB' 'ZZ' 'Z'
28 702 26 

Answer 12

JavaScript (Node.js), 48 bytes

f=([h,...t],p=0)=>h?f(t,p*26+parseInt(h,36)-9):p

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Answer 13

Java (JDK), 92 bytes

static int m(String v){int x=0;for(int i=0;i<v.length();i++)x=x*26+v.charAt(i)-64;return x;}

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Output

A=1

B=2

Z=26

AA=27

AB=28

AZ=52

ZZ=702

AAA=703

Answer 14

Google Sheets, 100 bytes

(formula evaluates to the result, takes input from cell A1)

=sum(arrayformula(
  (
    code(
      mid(A1,row(indirect("1:"&len(A1))),1)
    )-64
  )*26^row(indirect("1:"&len(A1)))/26

All spaces are added for clarity only.

Note.

• I don't know if it's possible to remove the duplication of row(indirect("1:"&len(A1)).
• Although Google Sheets has a decimal function, the transliteration would takes a lot of bytes.

Answer 15

APL+WIN, 12 bytes

Index origin 1.

26⊥¯65+⎕av⍳⎕

Try it online! Courtesy of Dyalog Classic

Explanation:

⎕av⍳⎕ Prompts for input and gets Ascii integer value for each character

¯65+ subtracts 65 to give integers 1-26 for A-Z

26⊥ converts resulting vector from base 26 to single integer

Answer 16

Japt -h, 10 bytes

åÈ*26+InYc

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Or without a flag. The first byte can be removed if we can take input as a character array.

¨c aI̓26

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---

Explanation

åÈ             :Cumulatively reduce by passing each character at Y through a function, with an initial total of 0
  *26          :  Multiply current total by 26
     -I        :  Subtract 64
       n       :   Subtracted from
        Yc     :    The codepoint of Y
               :Implicitly output the last element of the resulting array

Answer 17

MATL, 11 bytes

0w"26*@+64-

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Answer 18

Kotlin, 36 bytes

{it.fold(0){o,n->o*26+n.toInt()-64}}

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Answer 19

Ruby, 18 bytes

->s{[*?A..s].size}

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Answer 20

J, 11 bytes

26#.64|3&u:

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How it works

26#.64|3&u:  Monadic verb. Input: a string.
       3&u:  Convert each character to Unicode codepoint
    64|      Modulo 64; maps A -> 1, ... Z -> 26
26#.         Interpret as base-26 digits and convert to single integer

Answer 21

J, 20 bytes

[:(#.~26$~#)32|a.i.]

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Explanation:

 [:(#.~26$~#)32|a.i.] 
                  i.    - indices 
                    ]   - of the characters of the input
                a.      - in the alphabet
             32|        - mod 32
 [:(        )           - apply the following code to the above
         $~             - create a list of (left and right arguments exchanged) 
       26               - the number 26
           #            - repeated the length of the input times
    #.~                 - to base (26)

Answer 22

Ruby -nl, 39 bytes

p$_.chars.reduce(0){|x,y|26*x+y.ord-64}

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Answer 23

APL (Dyalog Classic), 11 bytes

⎕A∘⍳⊥⍨26⍴⍨≢

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Answer 24

Charcoal, 10 bytes

Ｉ↨²⁶ＥＳ⊕⌕αι

Try it online! Link is to verbose version of code. Explanation:

     Ｓ      Input string
    Ｅ       Map over characters
         ι  Current character
        α   Uppercase alphabet
       ⌕    Find index
      ⊕     Increment
  ²⁶        Literal 26
 ↨          Base conversion
Ｉ           Cast to string
            Implicitly print

Answer 25

x86 machine code, 19 bytes

00000000: 31c0 8b19 83e3 3f41 b21a f7e2 01d8 3831  1.....?A......81
00000010: 75f0 c3                                  u..

Assembly:

section .text
	global func
func:				;this function uses fastcall conventions
	xor eax, eax		;reset eax to 0
	loop:
		;ebx=*ecx%64
		mov ebx, [ecx]	;ecx is 1st arg to this func (in fastcall conventions)
		and ebx, 63	;because 64 is a pwr of 2,n%64=n&(64-1)

		;ecx++		get next char in str by incrementing ptr
		inc ecx
		
		;eax=eax*26
		mov dl, 26	;using an 8bit reg is less bytes
		mul edx
		
		;eax+=ebx //(eax=(*ecx%64)+(eax*26))
		add eax, ebx

		;if(*ecx!='\0')goto loop
		cmp byte [ecx], dh ;dh==0
		jne loop
	ret			;return value is in eax

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Answer 26

Kotlin, 29 bytes

{it.fold(0){a,v->v-'@'+a*26}}

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Explained

val column: (String) -> Int = {  // String in, Int out
    it.fold(0) { a, v ->  // acc, value
        v - '@'  // distance of char from @ (A=1 etc.)
                + a * 26
    }
}

Answer 27

Ahead, 22 bytes

>jvi'@-\26l
^~>O@ ~+*<

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Answer 28

MBASIC, 84 bytes

1 INPUT S$:L=LEN(S$):FOR I=1 TO L:V=ASC(MID$(S$,I,1))-64:T=T+26^(L-I)*V:NEXT:PRINT T

Output:

? AZ
 52

? ZZ
 702

? AAA
 703