Suppose I have string like
Harry potter was written by J. K. Rowling
How to split string using was and by as a delimiter and get result in vector in C++?
I know split using multiple char but not using multiple string.
-
What about the regex token iterator?: en.cppreference.com/w/cpp/regex/regex_token_iteratortgmath– tgmath2014-04-02 10:53:49 +00:00Commented Apr 2, 2014 at 10:53
-
I am trying not to use regex till its possible but a regex answer if possible for given example will also be helpful.psyche– psyche2014-04-02 10:57:06 +00:00Commented Apr 2, 2014 at 10:57
Add a comment
|
2 Answers
If you use c++11 and clang there is a solution using a regex string tokenizer:
#include <fstream>
#include <iostream>
#include <algorithm>
#include <iterator>
#include <regex>
int main()
{
std::string text = " Harry potter was written by J. K. Rowling.";
std::regex ws_re("(was)|(by)");
std::copy( std::sregex_token_iterator(text.begin(), text.end(), ws_re, -1),
std::sregex_token_iterator(),
std::ostream_iterator<std::string>(std::cout, "\n"));
}
The output is :
Harry potter
written
J. K. Rowling.
Sadly gcc4.8 does not have the regex fully integrated. But clang does compile and link this correctly.
1 Comment
psyche
BOOST is there if you can give example using boost then also it will be helpful.
Brute force approach, not boost, no c++11, optimizations more than welcome:
/** Split the string s by the delimiters, place the result in the
outgoing vector result */
void split(const std::string& s, const std::vector<std::string>& delims,
std::vector<std::string>& result)
{
// split the string into words
std::stringstream ss(s);
std::istream_iterator<std::string> begin(ss);
std::istream_iterator<std::string> end;
std::vector<std::string> splits(begin, end);
// then append the words together, except if they are delimiter
std::string current;
for(int i=0; i<splits.size(); i++)
{
if(std::find(delims.begin(), delims.end(), splits[i]) != delims.end())
{
result.push_back(current);
current = "";
}
else
{
current += splits[i] + " " ;
}
}
result.push_back(current.substr(0, current.size() - 1));
}
1 Comment
tgmath
The resulting whitespace at the end and beginning of tokens is not correct. E.g. for the example I get 'Harry potter ','written ','J. K. Rowling ' instead of 'Harry potter ',' written ',' J. K. Rowling'.