C++/STL Algorithms Non modifying sequence operations/search n
Use search_n to find four consecutive elements with value 3
<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. */
- include <iostream>
- include <vector>
- include <deque>
- include <list>
- include <set>
- include <map>
- include <string>
- include <algorithm>
- include <iterator>
- include <functional>
- 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; INSERT_ELEMENTS(coll,1,9); PRINT_ELEMENTS(coll); // find four consecutive elements with value 3 deque<int>::iterator pos; pos = search_n (coll.begin(), coll.end(), // range 4, // count 3); // value // print result if (pos != coll.end()) { cout << "four consecutive elements with value 3 " << "start with " << distance(coll.begin(),pos) +1 << ". element" << endl; } else { cout << "no four consecutive elements with value 3 found" << endl; }
} /* 1 2 3 4 5 6 7 8 9 no four consecutive elements with value 3 found
*/ </source>
Use search_n with custom function to find four consecutive elements with value greater than 3
<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. */
- include <iostream>
- include <vector>
- include <deque>
- include <list>
- include <set>
- include <map>
- include <string>
- include <algorithm>
- include <iterator>
- include <functional>
- 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; INSERT_ELEMENTS(coll,1,9); PRINT_ELEMENTS(coll); deque<int>::iterator pos; // find four consecutive elements with value greater than 3 pos = search_n (coll.begin(), coll.end(), // range 4, // count 3, // value greater<int>()); // criterion // print result if (pos != coll.end()) { << "start with " << distance(coll.begin(),pos) +1 << ". element" << endl; } else { << endl; }
} /* 1 2 3 4 5 6 7 8 9 four consecutive elements with value > 3 start with 4. element
*/ </source>