Algorithm (C++)

In the C++ programming language, algorithm is a function template that can work with (theoretically) any container containing values of any type. However, this is not always true because algorithms may have restrictions on the container/iterator category or even have requirements on the value type.

The C++ standard provides some standard algorithms collected in the standard header. All algorithms are in the std namespace.

A few of the most commonly used algorithms are:
* void copy(ForwardIterator source_begin, ForwardIterator source_end, ForwardIterator destination_begin)
* void fill(ForwardIterator destination_begin, ForwardIterator destination_end, T value)
* ForwardIterator find(ForwardIterator begin, ForwardIterator end, T search_object) (returns an iterator the found object or end if the object isn't found)
* T max(T a, T b) returns the greater of the two arguments
* ForwardIterator max_element(ForwardIterator begin, ForwardIterator end) finds the maximum element of a range
* T min(T a, T b) returns the smaller of the two arguments
* ForwardIterator min_element(ForwardIterator begin, ForwardIterator end) finds the minimum element of a range

Usage

#include #include #include using namespace std; int main() { vector v1(3, 42); // Create an array of three integers, all equal to 42. vector v2(5, 0); // Create an array of five integers, all zero. copy(v1.begin(), v1.end(), v2.begin()); // Copy all three elements from v1 to v2. // Now v2 contains { 42, 42, 42, 0, 0 }. fill(v1.begin(), v1.end(), 100); // Replace every element of v1 with "100". // Now v1 is { 100, 100, 100 }. if (find(v1.begin(), v1.end(), 0) = v1.end()) { // find() ends up at the last element of v1 since no results found // thus find() = vi.end() cout << "v1 doesn't contain a 0." << endl; // This will be the case. } else { cout << "v1 contains a 0." << endl; // This won't be the case since v1 is all 100s. } cout << "The bigger of 12.9 and 56.7 is " << max(12.9, 56.7) << "." << endl; // etc. return 0; }

External links

* [http://wwwasd.web.cern.ch/wwwasd/lhc++/RW/stdlibcr/classref.htm Standard C++ 1.2 Class Reference]