这是我的(代码高尔夫)挑战: 取两个字节数组,确定第二个数组是否是第一个数组的子字符串。如果是,则输出第一个数组中第二个数组内容出现的索引。如果在第一个数组中没有找到第二个数组,则输出-1。
示例输入: {63,101,245,215,0} {245,215}
预期产出:2
示例输入2:{24,55,74,3,1} {24,56,74}
预期输出2:-1
编辑:有人指出bool是多余的,所以你所要做的就是返回一个代表值索引的int,如果找不到则返回-1。
答案 0 :(得分:12)
Common lisp:
(defun golf-code (master-seq sub-seq) (search sub-seq master-seq))
答案 1 :(得分:8)
37个字符,功能比请求的更多:它返回所有匹配索引的列表。
I.@(([-:#@[{.>@])"_ 0(<@}."0 _~i.@#))
用法:
NB. Give this function a name i =: I.@(([-:#@[{.>@])"_ 0(<@}."0 _~i.@#)) NB. Test #1 245 215 i 63 101 245 215 0 2 NB. Test #2 - no results 24 56 74 i 24 55 74 3 1 NB. Test #3: matches in multiple locations 1 1 i 1 1 1 2 1 1 3 0 1 4 NB. Test #4: only exact substring matches 1 2 i 0 1 2 3 1 0 2 1 2 0 1 7
NB. list[0 to end], list[1 to end], list[2 to end], ...
<@}."0 _~i.@#
NB. Does the LHS completely match the RHS (truncated to match LHS)?
[-:#@[{.>@]
NB. boolean list of match/no match
([-:#@[{.>@])"_ 0(<@}."0 _~i.@#)
NB. indices of *true* elements
I.@(([-:#@[{.>@])"_ 0(<@}."0 _~i.@#))
答案 2 :(得分:7)
PostScript, 149 146 170 166 167 打击> 159个字符(在“做工作”部分):
% define data
/A [63 101 245 215 0] def
/S [245 215] def
% do the work
/d{def}def/i{ifelse}d/l S length 1 sub d/p l d[/C{dup[eq{pop -1}{dup S p
get eq{pop p 0 eq{]length}{/p p 1 sub d C}i}{p l eq{pop}if/p l d C}i}i}d
A aload pop C
% The stack now contains -1 or the position
请注意,如果子数组包含多次,则会查找 last 出现的情况。
修订历史记录:
false
替换为[[ne
,将true
替换为[[eq
以保存三个字符S
的最后一个元素在A
中出现两次,则删除可能导致误报的错误。不幸的是,这个错误修复有24个字符。解释版本:
不幸的是,SO语法高亮显示器不知道PostScript,因此可读性仍然有限。
/A [63 101 245 215 0] def
/S [245 215 ] def
/Slast S length 1 sub def % save the index of the last element of S,
% i.e. length-1
/Spos Slast def % our current position in S; this will vary
[ % put a mark on the bottom of the stack, we need this later.
/check % This function recursively removes values from the stack
% and compares them to the values in S
{
dup [
eq
{ % we found the mark on the bottom, i.e. we have no match
pop -1 % remove the mark and push the results
}
{ % we're not at the mark yet
dup % save the top value (part of the bugfix)
S Spos get
eq
{ % the top element of the stack is equal to S[Spos]
pop % remove the saved value, we don't need it
Spos 0
eq
{ % we are at the beginning of S, so the whole thing matched.
] length % Construct an array from the remaining values
% on the stack. This is the part of A before the match,
% so its length is equal to the position of the match.
% Hence we push the result and we're done.
}
{ % we're not at the beginning of S yet, so we have to keep comparing
/Spos Spos 1 sub def % decrease Spos
check % recurse
}
ifelse
}
{ % the top element of the stack is different from S[Spos]
Spos Slast eq {pop} if % leave the saved top value on the stack
% unless we're at the end of S, because in
% this case, we have to compare it to the
% last element of S (rest of the bugfix)
/Spos Slast def % go back to the end of S
check % recurse
}
ifelse
}
ifelse
}
def % end of the definition of check
A aload % put the contents of A onto the stack; this will also push A again,
% so we have to ...
pop % ...remove it again
check % And here we go!
答案 3 :(得分:6)
C99
#include <string.h>
void find_stuff(void const * const array1, const size_t array1length, /* Length in bytes, not elements */
void const * const array2, const size_t array2length, /* Length in bytes, not elements */
char * bReturnBool,
int * bReturnIndex)
{
void * found = memmem(array1, array1length, array2, array2length);
*bReturnBool = found != NULL;
*bReturnIndex = *bReturnBool ? found - array1 : -1;
}
简而言之,有点很麻烦:
#include <string.h>
#define f(a,b,c,d,e,f) { void * g = memmem(a, b, c, d); f = (e = !!g) ? g - a : -1; }
答案 4 :(得分:5)
基于 Nikhil Chelliah的answer kaiser.se的answer:
>>> t=lambda l,s:''.join(map(chr,l)).find(''.join(map(chr,s)))
>>> t([63, 101, 245, 215, 0], [245, 215])
2
>>> t([24, 55, 74, 3, 1], [24, 56, 74])
-1
部分感谢gnibbler:
>>> t=lambda l,s:bytes(l).find(bytes(s))
>>> t([63, 101, 245, 215, 0], [245, 215])
2
>>> t([24, 55, 74, 3, 1], [24, 56, 74])
-1
OP指定的参数顺序:
import List;t l s=maybe(-1)id$findIndex id$map(isPrefixOf s)$tails l
正如ephemient指出的那样,我们可以切换参数并将代码减少四个字符:
import List;t s=maybe(-1)id.findIndex id.map(isPrefixOf s).tails
答案 5 :(得分:4)
Ruby,使用Array#pack(41个字符集体):
def bytearray_search(a,b)
(i=b.pack('C*').index(b.pack('C*')))?i:-1
end
Perl(36个字符体,不包括参数处理):
sub bytearray_search {
($a,$b) = @_;
index(pack('C*',@$a),pack('C*',@$b))
}
答案 6 :(得分:4)
在Python中:
def test(large, small):
for i in range(len(large)):
if large[i:i+len(small)] == small:
return i
return -1
但是因为人们想要简洁,而不是优雅:
def f(l,s):
for i in range(len(l)):
if l[i:i+len(s)]==s:return i
return -1
这是75个字符,计算空格。
答案 7 :(得分:3)
Ruby 1.9(44B)
_=->a,b{[*a.each_cons(b.size)].index(b)||-1}
p _[[63, 101, 245, 215, 0], [245, 215]]
p _[[24, 55, 74, 3, 1], [24, 56, 74]]
goruby(29B)
_=->a,b{a.e_(b.sz).dx(b)||-1}
答案 8 :(得分:3)
Python中的另一个:
def subarray(large, small):
strsmall = ' '.join([str(c).zfill(3) for c in small])
strlarge = ' '.join([str(c).zfill(3) for c in large])
pos = strlarge.find(strsmall)
return ((pos>=0), pos//4)
答案 9 :(得分:3)
我觉得我在欺骗,但是使用Perl这会做OP想要的事情:
sub byte_substr {
use bytes;
index shift,shift
}
通常,Perl中的index()
适用于具有字符语义的字符串,但“use bytes”pragma使其使用字节语法。从联机帮助页:
当“使用字节”时 效果,暂时忽略编码,并处理每个字符串 作为一系列字节。
答案 10 :(得分:2)
Python3 36字节
基于Stephan202
>>> t=lambda l,s:bytes(l).find(bytes(s))
...
>>> t([63, 101, 245, 215, 0], [245, 215])
2
>>> t([24, 55, 74, 3, 1], [24, 56, 74])
-1
答案 11 :(得分:2)
Python oneliner函数定义,64个字符
def f(l,s): return ''.join(map(chr,l)).find(''.join(map(chr,s)))
由于我们显式传递一个字节数组,我们可以将其转换为Python的本机字节数组str
并使用str.find
答案 12 :(得分:2)
Python :84个字符
def f(a,b):
l=[a[i:i+len(b)]for i in range(len(a))]
return b in l and l.index(b)or-1
Prolog :84个字符(说“不”而不是返回-1):
s(X,[]).
s([H|T],[H|U]):-s(T,U).
f(X,Y,0):-s(X,Y).
f([_|T],Y,N):-f(T,Y,M),N is M+1.
答案 13 :(得分:1)
int m(byte[]a,int i,int y,byte[]b,int j,int z){return i<y?j<z?a[i]==b[j++]?m(a,++i,y,b,j,z):m(a,0,y,b,j,z):-1:j-y;}
Java,116个字符。有一些额外的功能投入。好的,所以它是一个kludge将启动条件和数组长度推入调用者。称之为:
m(byte[] substring, int substart, int sublength, byte[] bigstring, int bigstart, int biglength)
答案 14 :(得分:1)
<强>红宝石即可。这不是世界上最短的,但很酷,因为它是Array的扩展。
class Array
def contains other=[]
index = 0
begin
matched = 0
ndx = index
while other[matched] == self[ndx]
return index if (matched+1) == other.length
matched += 1
ndx += 1
end
end until (index+=1) == length
-1
end
end
puts [ 63, 101, 245, 215, 0 ].contains [245, 215]
# 2
puts [ 24, 55, 74, 3, 1 ].contains [24, 56, 74 ]
# -1
答案 15 :(得分:1)
PHP
在105 ......
function a_m($h,$n){$m=strstr(join(",",$h),join(",",$n));return$m?(count($h)-substr_count($m,",")-1):-1;}
或更明确地说,
function array_match($haystack,$needle){
$match = strstr (join(",",$haystack), join(",",$needle));
return $match?(count($haystack)-substr_count($match,",")-1):-1;
}
答案 16 :(得分:1)
GNU C:
int memfind(const char * haystack, size_t haystack_size, const char * needle,
size_t needle_size)
{
const char * match = memmem(haystack, hasystack_size, needle, needle_size);
return match ? match - haystack : -1;
}
ANSI C,没有库:
int memfind(const char * haystack, size_t haystack_size, const char * needle,
size_t needle_size)
{
size_t pos = 0;
for(; pos < haystack_size; ++pos)
{
size_t i = 0;
while(pos + i < haystack_size && i < needle_size &&
haystack[pos + i] == needle[i]) ++i;
if(i == needle_size) return pos;
}
return -1;
}
答案 17 :(得分:1)
C#,名为“a”和“b”的列表:
Enumerable.Range(-1, a.Count).Where(n => n == -1
|| a.Skip(n).Take(b.Count).SequenceEqual(b)).Take(2).Last();
如果您不关心返回第一个实例,您可以这样做:
Enumerable.Range(-1, a.Count).Last(n => n == -1
|| a.Skip(n).Take(b.Count).SequenceEqual(b));
答案 18 :(得分:1)
public class SubArrayMatch
{
private bool _IsMatch;
private int _ReturnIndex = -1;
private List<byte> _Input;
private List<byte> _SubArray;
private bool _Terminate = false;
#region "Public Properties"
public List<byte> Input {
set { _Input = value; }
}
public List<byte> SubArray {
set { _SubArray = value; }
}
public bool IsMatch {
get { return _IsMatch; }
}
public int ReturnIndex {
get { return _ReturnIndex; }
}
#endregion
#region "Constructor"
public SubArrayMatch(List<byte> parmInput, List<byte> parmSubArray)
{
this.Input = parmInput;
this.SubArray = parmSubArray;
}
#endregion
#region "Main Method"
public void MatchSubArry()
{
int _MaxIndex;
int _Index = -1;
_MaxIndex = _Input.Count - 1;
_IsMatch = false;
foreach (byte itm in _Input) {
_Index += 1;
if (_Terminate == false) {
if (SubMatch(_Index, _MaxIndex) == true) {
_ReturnIndex = _Index;
_IsMatch = true;
return;
}
}
else {
return;
}
}
}
private bool SubMatch(int BaseIndex, int MaxIndex)
{
int _MaxSubIndex;
byte _cmpByte;
int _itr = -1;
_MaxSubIndex = _SubArray.Count - 1;
_MaxSubIndex += 1;
if (_MaxSubIndex > MaxIndex) {
_Terminate = true;
return false;
}
foreach (byte itm in _SubArray) {
_itr += 1;
_cmpByte = _Input(BaseIndex + _itr);
if (!itm == _cmpByte) {
return false;
}
}
return true;
}
#endregion
}
Anhar Hussain Miah '编辑:Anhar.Miah @:03/07/2009
答案 19 :(得分:1)
在C#中:
private object[] test(byte[] a1, byte[] a2)
{
string s1 = System.Text.Encoding.ASCII.GetString(a1);
string s2 = System.Text.Encoding.ASCII.GetString(a2);
int pos = s1.IndexOf(s2, StringComparison.Ordinal);
return new object[] { (pos >= 0), pos };
}
用法示例:
byte[] a1 = new byte[] { 24, 55, 74, 3, 1 };
byte[] a2 = new byte[] { 24, 56, 74 };
object[] result = test(a1, a2);
Console.WriteLine("{0}, {1}", result[0], result[1]); // prints "False, -1"
答案 20 :(得分:1)
在Python中:
def SearchArray(input, search):
found = -1
for i in range(0, len(input) - len(search)):
for j in range(0, len(search)):
if input[i+j] == search[j]:
found = i
else:
found = -1
break
if found >= 0:
return True, found
else:
return False, -1
测试
print SearchArray([ 63, 101, 245, 215, 0 ], [ 245, 215 ])
print SearchArray([ 24, 55, 74, 3, 1 ], [ 24, 56, 74 ])
打印哪些:
(True, 2)
(False, -1)
请注意,有一个较短的解决方案,但它使用的python语言功能并不是真正可移植的。
答案 21 :(得分:0)
很奇怪,还没有人发布javascript ..
解决方案1:
r=s=b.length;s>=0&&(r=a.indexOf(b[0]));for(x=0;x<s;)b[x]!=a[r+x++]&&(r=-1);
function f(a, b) {
r = s = b.length;
if (s >= 0) r = a.indexOf(b[0]);
for (x = 0; x < s;)
if (b[x] != a[r + x++]) r = -1;
return r;
}
解决方案2:
r=m=-1;b.map(function(d){n=a.indexOf(d);r==m&&(c=r=n);if(n==m||c++!=n)r=m});
function f2(a, b) {
r = m = -1;
b.map(function (i) {
n = a.indexOf(i);
if (r == m) c = r = n;
if (n == m || c++ != n) r = m;
});
return r;
}
答案 22 :(得分:0)
实际函数只有 32字节,如果我们计算与J
相同{:b;:a,,{.a@>b,<b={}{;}if}%-1or}:f;
#Test cases (same as J) output
[63 110 245 215 0] [245 215] f p # [2]
[22 55 74 3 1] [24 56 74] f p # -1
[1 1 1 2 1 1 3] [1 1]f p # [0 1 4]
[0 1 2 3 1 0 2 1 2 0] [1 2] f p # [1 7]
答案 23 :(得分:0)
PHP AIR CODE 285字符
function f($a,$b){
if ( count($a) < 1 ) return -1;
if ( count($b) < 1 ) return -1;
if ( count($a) < count($b) ) return -1;
$x = array_shift($a);
$z = array_shift($b);
if ($x != $z){
$r = f( $x, array_unshift($z, $b) );
return (-1 == $r) ? -1 : 1 + $r;
}
$r = f($a, $b);
return (-1 == $r) ? -1 : 0;
}
答案 24 :(得分:0)
Ruby,看到Lar的代码后感到惭愧
def contains(a1, a2)
0.upto(a1.length-a2.length) { |i| return i if a1[i, a2.length] == a2 }
-1
end
答案 25 :(得分:0)
Haskell(114 Chars):
import Data.List
import Data.Maybe
g a b | elem b $ subsequences a = fromJust $ elemIndex (head b) a | otherwise = -1
答案 26 :(得分:0)
(defun golf-code (master-seq sub-seq)
(let ((x (search sub-seq master-seq)))
(values (not (null x)) (or x -1))))
答案 27 :(得分:0)
C#适用于具有相等运算符的任何类型:
first
.Select((index, item) =>
first
.Skip(index)
.Take(second.Count())
.SequenceEqual(second)
? index : -1)
.FirstOrDefault(i => i >= 0)
.Select(i => i => 0 ?
new { Found = true, Index = i }
:
new { Found = false, Index - 1 });
答案 28 :(得分:0)
在Ruby中:
def subset_match(array_one, array_two)
answer = [false, -1]
0.upto(array_one.length - 1) do |line|
right_hand = []
line.upto(line + array_two.length - 1) do |inner|
right_hand << array_one[inner]
end
if right_hand == array_two then answer = [true, line] end
end
return answer
end
实施例: IRB(主):151:0&GT; subset_match([24,55,74,3,1],[24,56,74]) =&GT; [false,-1]
IRB(主):152:0&GT; subset_match([63,101,245,215,0],[245,215]) =&GT; [true,2]
答案 29 :(得分:0)
C#:
public static object[] isSubArray(byte[] arr1, byte[] arr2) {
int o = arr1.TakeWhile((x, i) => !arr1.Skip(i).Take(arr2.Length).SequenceEqual(arr2)).Count();
return new object[] { o < arr1.Length, (o < arr1.Length) ? o : -1 };
}
答案 30 :(得分:0)
Lisp v1
(defun byte-array-subseqp (subarr arr)
(let ((found (loop
for start from 0 to (- (length arr) (length subarr))
when (loop
for item across subarr
for index from start below (length arr)
for same = (= item (aref arr index))
while same
finally (return same))
do (return start))))
(values (when found t) ; "real" boolean
(or found -1))))
Lisp v2(NB,subseq创建副本
(defun byte-array-subseqp (subarr arr)
(let* ((alength (length arr))
(slength (length subarr))
(found (loop
for start from 0 to (- alength slength)
when (equalp subarr (subseq arr start (+ start slength)))
do (return start))))
(values (when found t)
(or found -1))))
答案 31 :(得分:0)
这是使用字符串比较的C#版本。它工作正常,但对我来说感觉有点哈哈。
int FindSubArray(byte[] super, byte[] sub)
{
int i = BitConverter.ToString(super).IndexOf(BitConverter.ToString(sub));
return i < 0 ? i : i / 3;
}
// 106 characters
int F(byte[]x,byte[]y){int i=BitConverter.ToString(x)
.IndexOf(BitConverter.ToString(y));return i<0?i:i/3;}
这是一个稍长的版本,可以对每个单独的数组元素进行真正的比较。
int FindSubArray(byte[] super, byte[] sub)
{
int i, j;
for (i = super.Length - sub.Length; i >= 0; i--)
{
for (j = 0; j < sub.Length && super[i + j] == sub[j]; j++);
if (j >= sub.Length) break;
}
return i;
}
// 135 characters
int F(byte[]x,byte[]y){int i,j;for(i=x.Length-y.Length;i>=0;i--){for
(j=0;j<y.Length&&x[i+j]==y[j];j++);if(j>=y.Length)break;}return i;}
答案 32 :(得分:0)
由于Fredrik已使用STRING转换方式发布了代码。这是使用C#完成的另一种方式。
jwoolard打败了我,顺便说一下。我也使用了与他相同的算法。这是我们在大学时必须用C ++解决的问题之一。
public static bool Contains(byte[] parent, byte[] child, out int index)
{
index = -1;
for (int i = 0; i < parent.Length - child.Length; i++)
{
for (int j = 0; j < child.Length; j++)
{
if (parent[i + j] == child[j])
index = i;
else
{
index = -1;
break;
}
}
}
return (index >= 0);
}
答案 33 :(得分:-2)
<强> C#强>
列表:
public static int IndexOf<T>( List<T> list1, List<T> list2 )
{
return !list2.Except( list1 ).Any() ? list1.IndexOf( list2[0] ) : -1;
}
对于数组:
public static int IndexOf<T>( T[] arr1, T[] arr2 )
{
return !arr2.Except( arr1 ).Any() ? Array.IndexOf( arr1, arr2[0] ) : -1;
}