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 The partial sort copy algorithm sorts the smallest N elements, where N = min

The partial sort copy algorithm sorts the smallest N elements, where N = min partial_sort_copy Header <algorithm> template<class InputIterator, RandomAccessIterator> inline RandomAccessIterator partial_sort(InputIterator first1, InputIterator last1, RandomAccessIterator first2, RandomAccessIterator last2) The partial_sort_copy algorithm sorts the smallest N elements, where N = min((last1 - first1), (last2 - first2)), of the sequence [first1, last1) and copies the results to the sequence [first2, first2 + N]. The non-predicate version of partial_sort_copy uses operator< for comparisons. template<class InputIterator, RandomAccessIterator, class Compare> inline RandomAccessIterator partial_sort_copy(InputIterator first1, InputIterator last1, RandomAccessIterator first2, RandomAccessIterator last2, Compare compare) The partial_sort_copy algorithm sorts the smallest N elements, where N = min((last1 - first1), (last2 - first2)), of the sequence [first1, last1), and copies the results to the sequence [first2, first2 + N]. The predicate version of partial_sort_copy uses the compare function for comparisons. Samples Sample for Non-Predicate Version // disable warning C4786: symbol greater than 255 character, // okay to ignore #pragma warning(disable: 4786) #include <iostream> #include <algorithm> #include <functional> #include <vector> using namespace std ; void main() { const int VECTOR_SIZE = 8 ; // Define a template class vector of int typedef vector<int> IntVector ; //Define an iterator for template class vector of strings typedef IntVector::iterator IntVectorIt ; IntVector Numbers(VECTOR_SIZE) ; IntVector Result(4) ; IntVectorIt start, end, it ; // Initialize vector Numbers Numbers[0] = 4 ; Numbers[1] = 10; Numbers[2] = 70 ; Numbers[3] = 30 ; Numbers[4] = 10; Numbers[5] = 69 ; Numbers[6] = 96 ; Numbers[7] = 7; start = Numbers.begin() ; // location of first // element of Numbers end = Numbers.end() ; // one past the location // last element of Numbers cout << "Before calling partial_sort_copy\n" << endl ; // print content of Numbers cout << "Numbers { " ; for(it = start; it != end; it++) cout << *it << " " ; cout << " }\n" << endl ; // sort the smallest 4 elements in the Numbers // and copy the results in Result partial_sort_copy(start, end, Result.begin(), Result.end()) ; cout << "After calling partial_sort_copy\n" << endl ; cout << "Numbers { " ; for(it = start; it != end; it++) cout << *it << " " ; cout << " }\n" << endl ; cout << "Result { " ; for(it = Result.begin(); it != Result.end(); it++) cout << *it << " " ; cout << " }\n" << endl ; } Program Output Before calling partial_sort_copy Numbers { 4 10 70 30 10 69 96 7 } After calling partial_sort_copy Numbers { 4 10 70 30 10 69 96 7 } Result { 4 7 10 10 } Sample for Predicate Version // disable warning C4786: symbol greater than 255 character, // okay to ignore #pragma warning(disable: 4786) #include <iostream> #include <algorithm> #include <functional> #include <vector> using namespace std ; void main() { const int VECTOR_SIZE = 8 ; // Define a template class vector of int typedef vector<int> IntVector ; //Define an iterator for template class vector of strings typedef IntVector::iterator IntVectorIt ; IntVector Numbers(VECTOR_SIZE) ; IntVector Result(4) ; IntVectorIt start, end, it ; // Initialize vector Numbers Numbers[0] = 4 ; Numbers[1] = 10; Numbers[2] = 70 ; Numbers[3] = 30 ; Numbers[4] = 10; Numbers[5] = 69 ; Numbers[6] = 96 ; Numbers[7] = 7; start = Numbers.begin() ; // location of first // element of Numbers end = Numbers.end() ; // one past the location // last element of Numbers cout << "Before calling partial_sort_copy\n" << endl ; // print content of Numbers cout << "Numbers { " ; for(it = start; it != end; it++) cout << *it << " " ; cout << " }\n" << endl ; // sort the smallest 4 elements in the Numbers // and copy the results in Result partial_sort_copy(start, end, Result.begin(),Result.end(),less<int>()); cout << "After calling partial_sort_copy\n" << endl ; cout << "Numbers { " ; for(it = start; it != end; it++) cout << *it << " " ; cout << " }\n" << endl ; cout << "Result { " ; for(it = Result.begin(); it != Result.end(); it++) cout << *it << " " ; cout << " }\n" << endl ; } Program Output Before calling partial_sort_copy Numbers { 4 10 70 30 10 69 96 7 } After calling partial_sort_copy Numbers { 4 10 70 30 10 69 96 7 } Result { 4 7 10 10 }



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