Module: Standard C++ Library Library: Algorithms
Function
An algorithm that finds a subsequence within a sequence of values
#include <algorithm>
namespace std {
template <class ForwardIterator1, class ForwardIterator2>
ForwardIterator1 search(ForwardIterator1 start1,
ForwardIterator1 finish1,
ForwardIterator2 start2,
ForwardIterator2 finish2);
template <class ForwardIterator1,
class ForwardIterator2,
class BinaryPredicate>
ForwardIterator1 search(ForwardIterator1 start1,
ForwardIterator1 finish1,
ForwardIterator2 start2,
ForwardIterator2 finish2,
BinaryPredicate binary_pred);
template <class ForwardIterator, class Size, class T>
ForwardIterator search_n(ForwardIterator start,
ForwardIterator finish,
Size count, const T& value);
template <class ForwardIterator, class Size,
class T, class BinaryPredicate>
ForwardIterator search_n(ForwardIterator start
ForwardIterator finish,
Size count, const T& value,
BinaryPredicate pred)
}
The search() and search_n() algorithms search for a subsequence within a sequence. The search() algorithm searches for a subsequence [start2, finish2) within a sequence [start1, finish1), and returns the beginning location of the subsequence. If it does not find the subsequence, search() returns finish1. The first version of search() uses operator==() as a default, and the second version allows you to specify a binary predicate to perform the comparison.
The search_n() algorithm searches for the subsequence composed of count occurrences of value within a sequence [start, finish), and returns start if this subsequence is found. If it does not find the subsequence, search_n() returns finish. The first version of search_n() uses operator==() as a default, and the second version allows you to specify a binary predicate to perform the comparison.
search() performs at most (finish1 - start1)*(finish2-start2) applications of the corresponding predicate.
search_n() performs at most (finish - start)* count applications of the corresponding predicate.
//
// search.cpp
//
#include <algorithm>
#include <list>
#include <iostream>
int main ()
{
#ifndef _RWSTD_NO_NAMESPACE
using namespace std;
#endif
// Initialize a list sequence and subsequence with
// characters.
char seq[40] = "Here's a string with a substring in it";
char subseq[10] = "substring";
list<char,allocator<char> > sequence(seq, seq+38);
list<char,allocator<char> > subseqnc(subseq, subseq+9);
// Print out the original sequence.
cout << endl << "The subsequence, " << subseq
<< ", was found at the ";
cout << endl << "location identified by a '*'"
<< endl << " ";
// Create an iterator to identify the location of
// subsequence within sequence.
list<char,allocator<char> >::iterator place;
// Do search.
place = search(sequence.begin(), sequence.end(),
subseqnc.begin(), subseqnc.end());
// Identify result by marking first character with a '*'.
*place = '*';
// Output sequence to display result.
for (list<char,allocator<char> >::iterator i =
sequence.begin(); i != sequence.end(); i++)
cout << *i;
cout << endl;
return 0;
}
Program Output:
The subsequence, substring, was found at the
location identified by a '*'
Here's a string with a *ubstring in it
ISO/IEC 14882:1998 -- International Standard for Information Systems -- Programming Language C++, Section 25.1.9
Copyright (c) 1994-2006 Rogue Wave Software, a Quovadx Division.
Licensed under the Apache License, Version 2.0.
Contact Rogue Wave about documentation or support issues. You can also seek help from other developers through the Apache stdcxx community (see below).