양의 정수 배열과 두 개의 고유 한 유효한 인덱스가 주어지면 두 개의 인덱스에 해당하는 두 개의 요소가 바뀐 배열을 반환하십시오.

0 인덱싱 또는 1 인덱싱을 사용하도록 선택할 수 있지만 아래 테스트 사례는 0 인덱싱됩니다.

array        m n output
[1,2,3,4]    0 1 [2,1,3,4]
[5,8,9]      0 2 [9,8,5]
[11,13,15,3] 1 2 [11,15,13,3]
[11,13,15,3] 2 1 [11,15,13,3]
[11,15,15,3] 2 1 [11,15,15,3]

이것은 code-golf 입니다. 바이트 단위의 최단 답변이 이깁니다. 표준 허점이 적용됩니다.

기음/ C ++, 53 50 39 바이트

f(a,m,n)int*a;{a[m]^=a[n]^=a[m]^=a[n];}

온라인으로 사용해보십시오

@Dennis 덕분에 11 바이트 절약

인화점 스크립팅 언어, 98 95 바이트

f={t=_this;a=t select 0;b=+a;m=t select 1;n=t select 2;a set[m,b select n];a set[n,b select m]}

배열을 직접 수정합니다.

설명:

t=_this;                   // Give a shorter name for the array of arguments.

a=t select 0;              // Let 'a' be a pointer to the array that we modify.
                           // (The language doesn't have a concept of pointers really,
                           // yet its array variables are pointers to the actual array.)

b=+a;                      // Make a copy of the original array and save a pointer to it
                           // in the variable 'b'. This saves a few bytes later.

m=t select 1;              // Read the index arguments from the input array and save them
n=t select 2;              // to their respective variables.

a set[m,b select n];       // Do the swapping by reading the values from the copy and
a set[n,b select m]        // writing them to the original array. The last semicolon can
                           // be omitted because there are no more statements following 
                           // the last statement.

전화 :

array = [1,2,3,4];
str = format["%1", array];
[array, 0, 1] call f;
hint format["%1\n%2", str, array];

산출:

자바 스크립트 ES6, 36 32 바이트

봐봐, 임시 변수는 없어!

(a,m,n)=>[a[m],a[n]]=[a[n],a[m]]

• 에 4 바이트 감사를 저장 닐이 가져 오는 이 합의를 내 관심을.

시도 해봐

&에 대해서는 쉼표로 구분 된 요소 목록 a과 2 개의 정수를 입력하십시오 .mn

f=
(a,m,n)=>[a[m],a[n]]=[a[n],a[m]]
oninput=_=>o.innerText=(f(b=i.value.split`,`,+j.value,+k.value),b);o.innerText=(f(b=(i.value="5,8,9").split`,`,j.value=0,k.value=2),b)

*{font-family:sans-serif}input{margin:0 5px 0 0;width:100px;}#j,#k{width:50px;}

<label for=i>a: </label><input id=i><label for=j>m: </label><input id=j type=number><label for=k>n: </label><input id=k type=number><pre id=o>

파이썬 3 , 41 32 바이트

@notjagan 덕분에 -9 바이트

def f(a,m,n):a[m],a[n]=a[n],a[m]

온라인으로 사용해보십시오!

유효한 출력 형식 인 인수를 수정 합니다 .

젤리 , 7 바이트

Ṛ,ḷyJ}ị

온라인으로 사용해보십시오!

작동 원리

Ṛ,ḷyJ}ị  Main link. Left argument: [i, j]. Right argument: A (array)

Ṛ        Reverse; yield [j, i].
  ḷ      Left; yield [i, j].
 ,       Pair; yield [[j, i], [i, j]].
    J}   Indices right; yield all indices of A.
   y     Transliterate; replace j with i and i with j.
      ị  Index into A.

Japt , 17 16 바이트

hV(A=UgV UgW¹hWA

온라인으로 사용해보십시오!

ETHproduction 덕분에 바이트 절약

MATL , 7 6 바이트

yyP)w(

인덱스는 1부터 시작합니다.

온라인으로 사용해보십시오!

설명

입력을 고려 [11 13 15 3], [2 3].

yy   % Take two inputs implicitly. Duplicate them
     % STACK: [11 13 15 3], [2 3], [11 13 15 3], [2 3]
P    % Flip
     % STACK: [11 13 15 3], [2 3], [11 13 15 3], [3 2]
)    % Reference indexing (pick indexed entries)
     % STACK: [11 13 15 3], [2 3], [15 13]
w    % Swap
     % STACK: [11 13 15 3], [15 13], [2 3]
(    % Assignment indexing (write values into indexed entries). Implicitly display
     % STACK: [11 15 13 3]

C # (. NET 코어) , 48 43 31 바이트

(a,m,n)=>a[m]+=a[n]-(a[n]=a[m])

온라인으로 사용해보십시오!

임시 변수를 사용하지 않고 원래 배열의 숫자를 바꿉니다. 그럼에도 불구하고 나는이 답변이 Neil의 아이디어 였기 때문에 신용을 얻을 수 없습니다 .

공통 리스프 , 42 바이트

@coredump 덕분에 -2 바이트 .

(lambda(a i j)(rotatef(elt a i)(elt a j)))

온라인으로 사용해보십시오!

스왑 할 공통 Lisp 매크로가 있기 때문에 매우 간단합니다 rotatef.

자바 스크립트 ES6, 36 34 바이트

(a,m,n)=>(x=a[m],a[m]=a[n],a[n]=x)

• 함수가 배열을 변경하고 있기 때문에 -2 바이트. 배열을 반환 할 필요가 없습니다. @Neil에게 감사합니다

데모

f=

(a,m,n)=>(x=a[m],a[m]=a[n],a[n]=x)

let a1=[1,2,3,4], a2=[5,8,9], a3=[11,13,15,3]

f(a1,0,1);
f(a2,0,2);
f(a3,1,2);

console.log(JSON.stringify(a1)); //[2,1,3,4]
console.log(JSON.stringify(a2)); //[9,8,5]
console.log(JSON.stringify(a3)); //[11,15,13,3]

CJam , 4 바이트

{e\}

온라인으로 사용해보십시오!

자바 8 , 48 바이트

(a,b,c)->{int t=a[b];a[b]=a[c];a[c]=t;return a;}

입력:

int[] a
int b
int c

05AB1E, 10 bytes

D²è³ǝ¹³è²ǝ

Try it online!

Octave, 28 bytes

@(a,n){a(n)=a(flip(n)),a}{2}

Try it online!

Quite satisfied with this one actually :)

Takes input on the form: f([1,2,3,4],[1,2]), 1-indexed.

Explanation:

@(a,n)                         % Anonymous function that takes two 1-dimensional
                               % arrays as input
      {               , }      % Create a cell with two elements
       a(n)=a(flip(n))         % One element are the two number at indices given by
                               % the second input array. This will be a 1x2 array
      {a(n)=a(flip(n)),a}      % Place those two in a cell together with the entire array a
                               % a is now updated, thanks to Octave's inline assignment
      {a(n)=a(flip(n)),a}{2}   % Return the second element

Jellyfish, 7 bytes

p
ZRi
i

Takes a list and a pair of indices. Try it online!

Explanation

Jellyfish happens to have a "modify items at indices" function, Z, which does exactly what we need. The two is grab the inputs from STDIN. Z takes as arguments the second input, the reversal function R, and the list. Then Z performs the modification, and p prints the result.

R, 38 bytes

function(x,a,b){x[c(a,b)]=x[c(b,a)];x}

Feels rather long, but I can't get it much shorter. Sadly it requires the explicit returning through x, requiring {} around the function body. pryr::f() doesn't recognise the need for x as function argument so doesn't work :/.

Shenzhen I/O, 735 Bytes

23¥, 810 Power, 48 Lines of Code

[traces] 
......................
......................
......................
......................
......................
......................
.14.14.14.............
.94.14.14.............
.A........1C..........
.3554..95556..........
.9554.16..............
.A....................
.2....................
......................

[chip] 
[type] UC6
[x] 4
[y] 2
[code] 
  slx x0
  mov x1 acc
  mov x1 dat
  mov acc x3
  mov dat x3
  mov acc x3
  mov dat x3

[chip] 
[type] UC6
[x] 8
[y] 5
[code] 
  slx x2
  mov x2 x1
  mov x0 dat
  mov x2 x1
  mov x0 acc
  mov x2 x1
  mov dat 

[chip] 
[type] UC4X
[x] 2
[y] 6
[code] 
  slx x0
  mov 0 x3
j:  mov x0 acc
  mov acc x2
  teq acc 0
- jmp j
  mov -999 x1

[chip] 
[type] RAM
[x] 5
[y] 6

DISCLAIMER: Arrays are 0-terminated in this. Arrays are a pain in the ass to work with in Shenzhen I/O otherwise.

I actually made a steam level for this game. You can play it here.

EDIT: Aaand I just realized I said that the array in was ordered. Heck.

Swift, 111 65 bytes (0-indexed)

Swift is already notorious for being one of the worst code-golf languages, but here is a function that makes use of ternary expressions:

func t(l:[Int],m:Int,n:Int){var r=l;r[m]=l[n];r[n]=l[m];print(r)}

Check it out! - Usage: t(l:[1,2,3],m:0,n:1).

k (kona), 13 bytes

{x[y]:x@|y;x}

Pretty basic, but it works. Ex:

k){x[y]:x@|y;x}[1 2 3 4; 0 1]
2 1 3 4

Perl 5, 32 bytes

-3 bytes thanks to @Dom Hastings!

30 bytes of code + -pa flags.

@F[pop@p,@p]=@F[@p=<>];$_="@F"

Try it online!

Quite straight forward, using array slices.

Mathematica, 32 bytes

(a=#;a[[{##2}]]=a[[{#3,#2}]];a)&

C, 42 bytes

Modify the array in place with a temp value.

f(r,m,n){int*a=r;r=a[m];a[m]=a[n];a[n]=r;}

C, 60 58 bytes

A little more interesting, not using any temp value...

f(a,m,n)int*a;{a[m]+=a[n];a[n]-=a[m];a[n]*=-1;a[m]-=a[n];}

C, 49 bytes

Using XOR

f(a,m,n)int*a;{a[m]^=a[n];a[n]^=a[m];a[m]^=a[n];}

Pyth, 17 8 bytes

Saved 9 bytes thanks to Leaky Num.

@LQ.rUQE

Test it online!

This is 0-indexed, and the indices are provided as a tuple: (n, m).

Explanations

@LQ.rUQE

     UQ     # Generate [0, 1, 2, ..., len(input)]
       E    # Get the indices as the tuple (1, 2)
   .r       # Translate each element of UQ to its cyclic successor in E
            # Now the indices are permuted (e.g. [0, 2, 1, ..., len(input)]
@LQ         # For each index, get it's value. Implicit print

Mathematica, 20 bytes

#~Permute~Cycles@#2&

Pure function taking two arguments in the following 1-indexed (and possibly abusive) format: the second test case [5,8,9]; 0 2; [9,8,5] would be called as

#~Permute~Cycles@#2& [ {5,8,9} , {{1,3}} ]

(spaces are extraneous and just for visible parsing). Permute is the builtin function that applies a permutation to a list, and Cycles[{{a,b}}] represents the permutation that exchanges the ath and bth elements of a list and ignores the rest.

x86 Machine Code, 10 bytes

8B 04 8B 87 04 93 89 04 8B C3

This is a function written in 32-bit x86 machine code that swaps the values at the specified indices in a given array. The array is modified in-place, and the function does not return a value.

A custom calling convention is used, requiring the function's parameters to be passed in registers:

• The address of the array (pointer to its first element) is passed in the EBX register.
• The zero-based index of element A is passed in the ECX register.
  _{(Assumed to be a valid index.)}
• The zero-based index of element B is passed in the EDX register.
  _{(Assumed to be a valid index.)}

This keeps the size down and complies with all formal requirements, but does mean that the function cannot be easily called from other languages like C. You'd need to call it from another assembly-language program. (You could rewrite it to use any input registers, though, without affecting the byte count; there's nothing magical about the ones I chose.)

Ungolfed:

8B 04 8B     mov  eax, DWORD PTR [ebx+ecx*4]   ; get value of element A
87 04 93     xchg eax, DWORD PTR [ebx+edx*4]   ; swap element A and element B
89 04 8B     mov  DWORD PTR [ebx+ecx*4], eax   ; store new value for element A
C3           ret                               ; return, with array modified in-place

R, 34 bytes

pryr::f(`[<-`(a,c(m,n),a[c(n,m)]))

Java 8 + InverseY, 27 bytes

java.util.Collections::swap

Just calls the swap function... this is a method reference of the type Consumer3<List, Integer, Integer>.

Try it online! (header and footer for boilerplate & copy of Consumer3 interface)

JavaScript (ES2015), 66 57 49 bytes

A different (alas, longer) approach than previous JavaScript answers

(s,h,o,w=s.splice.bind(s))=>w(h,1,...w(o,1,s[h]))

Source

const swap = (arr, a, b, splice) => {
  splice(a, 1, ...splice(arr[b], 1, arr[a]))
}

awk, 31 bytes

{c=$a;$a=$b;$b=c;a=$1;b=$2}NR>1

Try it online!

Takes input in the format

1 2
1 2 3 4

and outputs as

2 1 3 4

(1-indexed).

Explanation

The entire program is a missing pattern with an action followed by a pattern with a missing action.

Since a missing pattern runs on each line, the code inside the braces runs for both input lines. The c=$a;$a=$b;$b=c; part swaps the two values at indices a and b (through the temporary variable c). This only has an effect on the second line, since on the first line a and b are not yet defined. The a=$1;b=$2 part defines a to be the first field and b to be the second field, which sets the appropriate values for the first part to run on the second line.

Since a missing action is equivalent to {print}, the pattern prints every line it matches. This pattern in particular is NR>1: that is, print whenever the line number is greater than 1, which happens to be line 2. This runs after the swapping of values has taken place, thus completing the task.

q/kdb+, 17 bytes

Solution:

{@[x;(|)y;:;x y]}

Example:

q){@[x;(|)y;:;x y]}[1 2 3 4;0 1]
2 1 3 4

Explanation:

A q version of the k answer by Simon. Apply the assign : function to x at indices reverse-y with value of x indexed at y. Broken down you can see more clearly:

q)x:1 2 3 4
q)y:0 1
q)x y
1 2
q)(|)y
1 0
q)x(|)y
2 1
q)@[x;(|)y;:;x y]
2 1 3 4