C++/STL Algorithms Merge/includes
Содержание
- 1 Container includes: generic includes algorithm
- 2 Determine whether one set is completely contained in another set
- 3 Use includes and search to check whether all elements in search are also in coll
- 4 Use includes() function to check if one set contains another set
- 5 Use includes() to check for subset
Container includes: generic includes algorithm
<source lang="cpp">
- include <iostream>
- include <cassert>
- include <algorithm>
- include <vector>
using namespace std; int main() {
bool result; string s("abcde"); string s2("aeiou"); vector<char> vector1(s.begin(), s.end()); vector<char> vector2(s2.begin(), s2.end()); // Illustrate includes: result = includes(vector1.begin(), vector1.end(),vector2.begin(), vector2.end()); assert (result == false); result = includes(vector1.begin(), vector1.end(),vector2.begin(), vector2.begin() + 2); // "a" and "e" are contained in vector1 assert (result == true); return 0;
}
</source>
Determine whether one set is completely contained in another set
<source lang="cpp">
- include <iostream>
using std::cout; using std::endl;
- include <algorithm>
- include <iterator>
int main() {
const int SIZE1 = 10, SIZE2 = 5, SIZE3 = 20; int a1[ SIZE1 ] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; int a2[ SIZE2 ] = { 4, 5, 6, 7, 8 }; int a3[ SIZE2 ] = { 4, 5, 6, 11, 15 }; std::ostream_iterator< int > output( cout, " " ); std::copy( a1, a1 + SIZE1, output ); cout << "\n"; std::copy( a2, a2 + SIZE2, output ); cout << "\n"; std::copy( a3, a3 + SIZE2, output ); if ( std::includes( a1, a1 + SIZE1, a2, a2 + SIZE2 ) ) cout << "\n\na1 includes a2"; else cout << "\n\na1 does not include a2"; return 0;
} /* 1 2 3 4 5 6 7 8 9 10 4 5 6 7 8 4 5 6 11 15 a1 includes a2
*/ </source>
Use includes and search to check whether all elements in search are also in coll
<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() {
list<int> coll; vector<int> search; INSERT_ELEMENTS(coll,1,9); PRINT_ELEMENTS(coll,"coll: "); search.push_back(3); search.push_back(4); search.push_back(7); PRINT_ELEMENTS(search,"search: "); // check whether all elements in search are also in coll if (includes (coll.begin(), coll.end(), search.begin(), search.end())) { cout << "all elements of search are also in coll" << endl; } else { cout << "not all elements of search are also in coll" << endl; }
} /* coll: 1 2 3 4 5 6 7 8 9 search: 3 4 7 all elements of search are also in coll
*/ </source>
Use includes() function to check if one set contains another set
<source lang="cpp">
- include <algorithm>
- include <iostream>
- include <vector>
using namespace std;
void print(int elem) {
cout << elem << " ";
} int main(int argc, char** argv) {
vector<int> setOne, setTwo, setThree; setOne.push_back(1); setOne.push_back(2); setOne.push_back(3); setTwo.push_back(2); setTwo.push_back(3); setTwo.push_back(4); // set algorithms work on sorted ranges sort(setOne.begin(), setOne.end()); sort(setTwo.begin(), setTwo.end()); if (includes(setOne.begin(), setOne.end(), setTwo.begin(), setTwo.end())) { cout << "The second set is a subset of the first\n"; } if (includes(setTwo.begin(), setTwo.end(), setOne.begin(), setOne.end())) { cout << "The first set is a subset of the second\n"; } return (0);
}
</source>
Use includes() to check for subset
<source lang="cpp">
- include <iostream>
- include <list>
- include <algorithm>
using namespace std; template<class InIter> void show_range(const char *msg, InIter start, InIter end); int main() {
list<char> list1, list2, result(15), list3; list<char>::iterator res_end; for(int i=0; i < 5; i++) list1.push_back("A"+i); for(int i=3; i < 10; i++) list2.push_back("A"+i); show_range("Contents of list1: ", list1.begin(), list1.end()); list3.push_back("A"); list3.push_back("C"); list3.push_back("D"); if(includes(list1.begin(), list1.end(),list3.begin(), list3.end())) cout << "list3 is a subset of list1" << endl; else cout << "list3 is not a subset of list1" << endl; return 0;
} template<class InIter> void show_range(const char *msg, InIter start, InIter end) {
InIter itr; cout << msg << endl; for(itr = start; itr != end; ++itr) cout << *itr << endl;
}
</source>