C++/STL Algorithms Merge/set symmetric difference
Determine difference the ranges with set_symmetric_difference()
<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() {
int c1[] = { 1, 2, 2, 4, 6, 7, 7, 9 }; int num1 = sizeof(c1) / sizeof(int); int c2[] = { 2, 2, 2, 3, 6, 6, 8, 9 }; int num2 = sizeof(c2) / sizeof(int); // print source ranges cout << "c1: " ; copy (c1, c1+num1, ostream_iterator<int>(cout," ")); cout << endl; cout << "c2: " ; copy (c2, c2+num2, ostream_iterator<int>(cout," ")); cout << "\n" << endl; // determine difference the ranges with set_symmetric_difference() cout << "set_symmetric_difference(): "; set_symmetric_difference (c1, c1+num1, c2, c2+num2, ostream_iterator<int>(cout," ")); cout << endl;
} /* c1: 1 2 2 4 6 7 7 9 c2: 2 2 2 3 6 6 8 9 set_symmetric_difference(): 1 2 3 4 6 7 7 8
*/ </source>
Determine elements in set A that are not in set B and elements of set B that are not in set A
<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 ); int symmetric_difference[ SIZE1 + SIZE2 ]; int *ptr = std::set_symmetric_difference( a1, a1 + SIZE1, a3, a3 + SIZE2, symmetric_difference ); cout << "set_symmetric_difference of a1 and a3 is: "; std::copy( symmetric_difference, ptr, output ); return 0;
} /* 1 2 3 4 5 6 7 8 9 10 4 5 6 7 8 4 5 6 11 15 set_symmetric_difference of a1 and a3 is: 1 2 3 7 8 9 10 11 15
*/ </source>
Illustrate set_symmetric_difference
<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()); vector<char> setDifference; set_symmetric_difference(vector1.begin(),vector1.end(),vector2.begin(), vector2.end(),back_inserter(setDifference)); for(int i=0;i<setDifference.size();i++){ cout << setDifference[i]; } return 0;
} /* bcdiou
*/ </source>