STL_Set

#include <iostream>
#include <fstream>
#include <vector>
#include <set>
#include <algorithm>
#include <string>

#define ONE_OR_TWO (rand()%2)
#define _vec_BEGIN_END _vec.begin(), _vec.end()
#define _FF_BEGIN_END first_fisher.begin(), first_fisher.end()
#define _SF_BEGIN_END second_fisher.begin(), second_fisher.end()
#define _TF_BEGIN_END third_fisher.begin(), third_fisher.end()
#define _FU_BEGIN_END fish_union.begin(), fish_union.end()
#define _FD_BEGIN_END all_fish.begin(), all_fish.end()

using namespace std;

void read_file_1(vector<string>& _vec, string file);
void read_file_2(vector<string>& _vec, string file);

void print_set(set<string> _set);

int main() {
    //-----------------------------------------------------------------------------------------------------
    vector<string> _vec;
//    read_file_1(_vec, "input.txt"); //no iter
    read_file_2(_vec, "input.txt"); //stream iter
    //Make set all_fish
    set<string> all_fish;
    copy(_vec.begin(), _vec.end(), inserter(all_fish, all_fish.begin()));
    //Print set all_fish
    ostream_iterator<string> o_iter(cout, " "); //как связываются??
    cout<<"Рыбы в озере: ";
    copy(all_fish.begin(), all_fish.end(), o_iter);
    cout<<endl;
    //-----------------------------------------------------------------------------------------------------
    srand((int)time(NULL));
    //Make set first_fisher
    set<string> first_fisher;
    for_each(_vec_BEGIN_END , [&first_fisher](string fish){ if(ONE_OR_TWO%2==0) first_fisher.insert(fish);});
    //Print set first_fisher
    cout<<"Первый рыбак: ";
    print_set(first_fisher);
    cout<<endl;
    //-----------------------------------------------------------------------------------------------------
    //Make set second_fisher
    set<string> second_fisher;
    for_each(_vec_BEGIN_END , [&second_fisher](string fish){ if(ONE_OR_TWO%2==0) second_fisher.insert(fish);});
    //Print set second_fisher
    cout<<"Второй рыбак: ";
    print_set(second_fisher);
    cout<<endl;
    //-----------------------------------------------------------------------------------------------------
    //Make set third_fisher
    set<string> third_fisher;
    for_each(_vec_BEGIN_END , [&third_fisher](string fish){ if(ONE_OR_TWO%2==0) third_fisher.insert(fish);});
    //Print set third_fisher
    cout<<"Третий рыбак: ";
    print_set(third_fisher);
    cout<<endl;
    //----------------------------------------------------------------------------------------------------
    //Make union
    set<string> fish_union;
    set_union(_FF_BEGIN_END, _SF_BEGIN_END, inserter(fish_union, fish_union.begin()));
    set_union(_FU_BEGIN_END, _TF_BEGIN_END, inserter(fish_union, fish_union.begin()));
    //Print union
    cout<<"Рыбы, которые есть хотя бы у одного рыбака: ";
    print_set(fish_union);
    cout<<endl;
    //----------------------------------------------------------------------------------------------------
    //Make diff
    set<string> fish_diff;
    set_difference(_FD_BEGIN_END, _FU_BEGIN_END, inserter(fish_diff, fish_diff.begin()));
    //Print diff
    cout<<"Рыбы, которые есть в озере, но не в улове любого из рыбаков: ";
    print_set(fish_diff);
    cout<<endl;
    return 0;
}

void print_set(set<string> _set){
    ostream_iterator<string> o_iter(cout, " ");
    copy(_set.begin(), _set.end(), o_iter);
}

void read_file_1(vector<string>& _vec, string file_name){
    //Open file
    fstream ifile;
    ifile.open(file_name);
    //Read input.txt
    if(ifile.is_open()){
        string buff;
        while(!ifile.eof()){
            ifile>>buff;
            _vec.push_back(buff);
        }
    }
    //End reading
    ifile.close();
}

void read_file_2(vector<string>& _vec, string file_name){
    //Open file
    fstream ifile;
    ifile.open(file_name);
    //Read input.txt
    istream_iterator<string> initer(ifile), endinter;
    copy(initer, endinter, back_inserter(_vec));
    //End reading
    ifile.close();
}