mirror of
https://gitlab.com/sortix/sortix.git
synced 2023-02-13 20:55:38 -05:00
45 lines
1.5 KiB
C++
45 lines
1.5 KiB
C++
/*******************************************************************************
|
|
|
|
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012.
|
|
|
|
This file is part of the Sortix C Library.
|
|
|
|
The Sortix C Library is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU Lesser General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or (at your
|
|
option) any later version.
|
|
|
|
The Sortix C Library is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
|
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
|
|
License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public License
|
|
along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
strstr.cpp
|
|
Locate a substring.
|
|
|
|
*******************************************************************************/
|
|
|
|
#include <string.h>
|
|
|
|
// TODO: This simple and hacky implementation runs in O(N^2) even though this
|
|
// problem can be solved in O(N).
|
|
extern "C" char* strstr(const char* haystack, const char* needle)
|
|
{
|
|
if ( !needle[0] )
|
|
return (char*) haystack;
|
|
for ( size_t i = 0; haystack[i]; i++ )
|
|
{
|
|
bool diff = false;
|
|
for ( size_t j = 0; needle[j]; j++ )
|
|
{
|
|
if ( haystack[i+j] != needle[j] ) { diff = true; break; }
|
|
}
|
|
if ( diff )
|
|
continue;
|
|
return (char*) haystack + i;
|
|
}
|
|
return NULL;
|
|
}
|