C++ Tutorial/STL Algorithms Non modifying sequence operations/search

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Search first occurrence

<source lang="cpp">/* The following code example is taken from the book

* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
  1. include <iostream>
  2. include <vector>
  3. include <deque>
  4. include <list>
  5. include <set>
  6. include <map>
  7. include <string>
  8. include <algorithm>
  9. include <iterator>
  10. include <functional>
  11. include <numeric>

/* PRINT_ELEMENTS()

* - prints optional C-string optcstr followed by
* - all elements of the collection coll
* - separated by spaces
*/

template <class T> inline void PRINT_ELEMENTS (const T& coll, const char* optcstr="") {

   typename T::const_iterator pos;
   std::cout << optcstr;
   for (pos=coll.begin(); pos!=coll.end(); ++pos) {
       std::cout << *pos << " ";
   }
   std::cout << std::endl;

} /* INSERT_ELEMENTS (collection, first, last)

* - fill values from first to last into the collection
* - NOTE: NO half-open range
*/

template <class T> inline void INSERT_ELEMENTS (T& coll, int first, int last) {

   for (int i=first; i<=last; ++i) {
       coll.insert(coll.end(),i);
   }

} using namespace std; int main() {

   deque<int> coll;
   list<int> subcoll;
   INSERT_ELEMENTS(coll,1,7);
   INSERT_ELEMENTS(coll,1,7);
   INSERT_ELEMENTS(subcoll,3,6);
   PRINT_ELEMENTS(coll,   "coll:    ");
   PRINT_ELEMENTS(subcoll,"subcoll: ");
   // search first occurrence of subcoll in coll
   deque<int>::iterator pos;
   pos = search (coll.begin(), coll.end(),         // range
                 subcoll.begin(), subcoll.end());  // subrange
   // loop while subcoll found as subrange of coll
   while (pos != coll.end()) { 
       // print position of first element
       cout << "subcoll found starting with element "
            << distance(coll.begin(),pos) + 1
            << endl;
       // search next occurrence of subcoll
       ++pos;
       pos = search (pos, coll.end(),                  // range
                     subcoll.begin(), subcoll.end());  // subrange
   }

}</source>

coll:    1 2 3 4 5 6 7 1 2 3 4 5 6 7
subcoll: 3 4 5 6
subcoll found starting with element 3
subcoll found starting with element 10

Search first subrange

<source lang="cpp">/* The following code example is taken from the book

* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
  1. include <iostream>
  2. include <vector>
  3. include <deque>
  4. include <list>
  5. include <set>
  6. include <map>
  7. include <string>
  8. include <algorithm>
  9. include <iterator>
  10. include <functional>
  11. include <numeric>

/* PRINT_ELEMENTS()

* - prints optional C-string optcstr followed by
* - all elements of the collection coll
* - separated by spaces
*/

template <class T> inline void PRINT_ELEMENTS (const T& coll, const char* optcstr="") {

   typename T::const_iterator pos;
   std::cout << optcstr;
   for (pos=coll.begin(); pos!=coll.end(); ++pos) {
       std::cout << *pos << " ";
   }
   std::cout << std::endl;

} /* INSERT_ELEMENTS (collection, first, last)

* - fill values from first to last into the collection
* - NOTE: NO half-open range
*/

template <class T> inline void INSERT_ELEMENTS (T& coll, int first, int last) {

   for (int i=first; i<=last; ++i) {
       coll.insert(coll.end(),i);
   }

} using namespace std; // checks whether an element is even or odd bool checkEven (int elem, bool even) {

   if (even) {
       return elem  2 == 0;
   }
   else {
       return elem  2 == 1;
   }

} int main() {

   vector<int> coll;
   INSERT_ELEMENTS(coll,1,9);
   PRINT_ELEMENTS(coll,"coll: ");
   /* arguments for checkEven()
    * - check for: ""even odd even""
    */
   bool checkEvenArgs[3] = { true, false, true };
   // search first subrange in coll
   vector<int>::iterator pos;
   pos = search (coll.begin(), coll.end(),       // range
                 checkEvenArgs, checkEvenArgs+3, // subrange values
                 checkEven);                     // subrange criterion
   // loop while subrange found
   while (pos != coll.end()) {
       // print position of first element
       cout << "subrange found starting with element "
            << distance(coll.begin(),pos) + 1
            << endl;
       // search next subrange in coll
       pos = search (++pos, coll.end(),              // range
                     checkEvenArgs, checkEvenArgs+3, // subr. values
                     checkEven);                     // subr. criterion
   }

}</source>

coll: 1 2 3 4 5 6 7 8 9
subrange found starting with element 2
subrange found starting with element 4
subrange found starting with element 6