[ новости /+++ | форум | теги | ]

                       Standard C++ Library
             Copyright 1998, Rogue Wave Software, Inc.


NAME
     search, search_n

      - Finds a sub-sequence within a sequence of values that  is
     element-wise equal to the values in an indicated range.



SYNOPSIS
     #include <algorithm>
     template <class ForwardIterator1, class ForwardIterator2>
     ForwardIterator1 search (ForwardIterator1 first1,
                              ForwardIterator1 last1,
                              ForwardIterator2 first2,
                              ForwardIterator2 last2);

     template <class ForwardIterator1,
              class ForwardIterator2,
              class BinaryPredicate>
     ForwardIterator1 search (ForwardIterator1 first1,
                              ForwardIterator1 last1,
                              ForwardIterator2 first2,
                              ForwardIterator2 last2,
                              BinaryPredicate binary_pred);

     template <class ForwardIterator,
              class Size,
              class T>
     ForwardIterator search_n (ForwardIterator first,
                              ForwardIterator last,
                              Size count, const T& value);

     template <class ForwardIterator,
              class Size,
              class T,
              class BinaryPredicate>
     ForwardIterator search_n (ForwardIterator first,
                              ForwardIterator last,
                              Size count, const T& value,
                              BinaryPredicate pred)



DESCRIPTION
     The search and search_n algorithms search for a sub-sequence
     within  a sequence. The search algorithm searches for a sub-
     sequence [first2, last2) within a sequence [first1,  last1),
     and returns the beginning location of the sub-sequence.   If
     it does not find the sub-sequence, search returns last1. The
     first version of search uses the equality (==) 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  sub-sequence  com-
     posed  of  count  occurrences  of  value  within  a sequence
     [first, last), and returns first  if  this  sub-sequence  is
     found.    If    it   does   not   find   the   sub-sequence,
     search_n_returns last. The first version  of  search_n  uses
     the equality (==) operator as a default, and the second ver-
     sion allows you to specify a binary predicate to perform the
     comparison.



COMPLEXITY
     search performs  at  most  (last1  -  first1)*(last2-first2)
     applications of the corresponding predicate.

     search_n performs at most (last - first)* count applications
     of the corresponding predicate.



EXAMPLE
     //
     // search.cpp
     //
      #include <algorithm>
      #include <list>
      #include <iostream>
     using namespace std;

     int main()
      {
        // Initialize a list sequence and
        // sub-sequence with characters
       char seq[40] = "Here's a string with a substring in it";
       char subseq[10] = "substring";
       list<char> sequence(seq, seq+39);
       list<char> subseqnc(subseq, subseq+9);

        //Print out the original sequence
       cout << endl << "The sub-sequence, " << subseq
             << ", was found at the ";
       cout << endl << "location identified by a '*'"
             << endl << "     ";

        // Create an iterator to identify the location of
        // sub-sequence within sequence
       list<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>::iterator i = sequence.begin();
               i != sequence.end(); i++)
         cout << *i;
       cout << endl;

       return 0;
      }

     Program Output



     The sub-sequence, substring, was found at the
     location identified by a '*'
         Here's a string with a *substring in it



WARNINGS
     If your compiler does not support default  template  parame-
     ters,  then you always need to supply the Allocator template
     argument. For instance, you need to write:

     list<char, allocator<char> >

     instead of:

     list<char>

     If your compiler does not support namespaces,  then  you  do
     not need the using declaration for std.

     <ENDNOTES> </ENDNOTES>

Партнёры:

Хостинг: