We need not sort all elements sometimes. Here are a few simple examples of STL algorithms partial_sort, nth_element, and partition. partial_sort For example, find the 5 biggest ones in 10 random numbers. #include <iostream> #include <vector> #include <cstdlib> #include <ctime> #include <algorithm> using namespace std; int main() { vector<int> values; Read more…
accumulate Interval algorithm accumulate supports custom calculate method to count elemeints in the special range. We can use it to get summary, multiple, average and etc of some elements, it’s very convenient and powerful. The syntax and usage example are in the following. Syntax: template< class InputIt, class T > Read more…
count STL algorithm count can help us to count the elements that are equal to value.Its syntax is like the following form: C++ template typename iterator_traits::difference_type count( InputIt first, InputIt last, const T &value ); Example: C++ #include #include #include using namespace std; int main(int argc, char *argv[]) { vector Read more…
The algorithm copy_if is useful, it can help us to get all elements that meet special conditions. C++ template OutputIt copy_if( InputIt first, InputIt last, OutputIt d_first, UnaryPredicate pred ); Possible implement: C++ template OutputIt copy_if(InputIt first, InputIt last, OutputIt d_first, UnaryPredicate pred) { while (first != last) { if Read more…
STL Algorithm std::lexicographical_compare is an algorithm which can be used to compare string lexicographically.We can give our comparing function to make it work without pay attention to capital and small letter. C++ template constexpr bool lexicographical_compare( InputIt1 first1, InputIt1 last1, InputIt2 first2, InputIt2 last2, Compare comp ); Example: C++ #include Read more…
std::unique_copy is an algorithm which can be used to copy elements without duplicating objects in adjacent locations. template< class InputIt, class OutputIt > OutputIt uniquecopy( InputIt first, InputIt last, OutputIt dfirst ); Usage example: C++ #include #include #include #include int main() { std::string s1 = “This is a story about Read more…