Exer14_40.cpp

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cstddef>
using std::cout;
using std::endl;
using std::string;
using std::vector;
using std::size_t;
class CompareSize {
public:
    bool operator()(const string &s1, const string &s2) const { return s1.size() < s2.size(); }
};
class IsLonger {
    // Note: members that define types must appear before they are used(on page 272)
    using size_type = vector<string>::size_type;
public:
    IsLonger(size_type sz) : size(sz) {}
    bool operator()(const string &s) const { return s.size() >= size; }
private:
    size_type size;
};
class OutputStr {
public:
    void operator()(const string &s) const { cout << s << " "; }
};
string make_plural(size_t ctr, const string &word, const string &ending)
{
    return (ctr > 1) ? word + ending : word;
}
void elimDup(vector<string> &words)
{
    sort(words.begin(), words.end());
    auto end_unique = unique(words.begin(), words.end());
    words.erase(end_unique, words.end());
}
void biggie(vector<string> &words, vector<string>::size_type sz)
{
    // put words in alphabetical order and remove duplicate
    elimDup(words);
    // sort words by size, but maintain alphabetical order for words of the same size
    stable_sort(words.begin(), words.end(), CompareSize());
    // get an iterator to the first element whose size() is >= sz
    auto wc = find_if(words.begin(), words.end(), IsLonger(sz));
    // compute the number of elements with size >= sz
    auto count = words.end() - wc;
    cout << count << " " << make_plural(count, "word", "s") << " of length "
         << sz << " or longer" << endl;
    // put words of the given size or longer, each one followed by a space
    for_each(wc, words.end(), OutputStr());
    cout << endl;
}
int main()
{
    vector<string> words = { "the", "quick", "red", "fox", "jump", "over", "the", "slow", "red", "turtle" };
    biggie(words, 3);
    return 0;
}