C++ Cookbook

7.6. Sorting a Range

Problem

You have a range of elements that you need to sort.

Solution

There are a handful of algorithms you can use for sorting a range. You can do a conventional sort (ascending or descending order) with sort, defined in <algorithm>, or you can use one of the other sorting functions, such as partial_sort . Have a look at Example 7-6 to see how.

Example 7-6. Sorting

#include <iostream> #include <istream> #include <string> #include <list> #include <vector> #include <algorithm> #include <iterator> #include "utils.h" // For printContainer(): see 7.10 using namespace std; int main() { cout << "Enter a series of strings: "; istream_iterator<string> start(cin); istream_iterator<string> end; // This creates a "marker" vector<string> v(start, end); // The sort standard algorithm will sort elements in a range. It // requires a random-access iterator, so it works for a vector. sort(v.begin(), v.end()); printContainer(v); random_shuffle(v.begin(), v.end()); // See 7.2 string* arr = new string[v.size()]; // Copy the elements into the array copy(v.begin(), v.end(), &arr[0]); // Sort works on any kind of range, so long as its arguments // behave like random-access iterators. sort(&arr[0], &arr[v.size()]); printRange(&arr[0], &arr[v.size()]); // Create a list with the same elements list<string> lst(v.begin(), v.end()); lst.sort(); // The standalone version of sort won't work; you have // to use list::sort. Note, consequently, that you // can't sort only parts of a list. printContainer(lst); ...