algo/lexicocmp1.cpp

The following code example is taken from the book
The C++ Standard Library - A Tutorial and Reference, 2nd Edition
by Nicolai M. Josuttis, Addison Wesley Longman, 2012
Copyright © 2012 by Pearson Education, Inc. and Nicolai M. Josuttis


#include "algostuff.hpp"
using namespace std;

void printCollection (const list<int>& l)
{
    PRINT_ELEMENTS(l);
}

bool lessForCollection (const list<int>& l1, const list<int>& l2)
{
    return lexicographical_compare
                (l1.cbegin(), l1.cend(),   // first range
                 l2.cbegin(), l2.cend());  // second range
}

int main()
{
    list<int> c1, c2, c3, c4;

    // fill all collections with the same starting values
    INSERT_ELEMENTS(c1,1,5);
    c4 = c3 = c2 = c1;

    // and now some differences
    c1.push_back(7);
    c3.push_back(2);
    c3.push_back(0);
    c4.push_back(2);

    // create collection of collections
    vector<list<int>> cc;
    cc.insert ( cc.begin(), { c1, c2, c3, c4, c3, c1, c4, c2 } );

    // print all collections
    for_each (cc.cbegin(), cc.cend(),
              printCollection);
    cout << endl;

    // sort collection lexicographically
    sort (cc.begin(), cc.end(),    // range
          lessForCollection);      // sorting criterion

    // print all collections again
    for_each (cc.cbegin(), cc.cend(),
              printCollection);
}