// this program demonstrates experimentally than when we AND together any number of inequalities (>0)
// we select a single range which may be open on one end only, or closed; or we select nothing

#include <iostream>
#include <random>
#include <functional>
#include <map>
#include <sstream>

int main()
{
    std::default_random_engine generator(time(0)/*seed*/);
    std::geometric_distribution<int> terms_dist(0.3);
    std::uniform_int_distribution<int> operation_dist(0, 3); // <, >, <=, >=
    std::uniform_int_distribution<int> value_dist(-10, 10);
  
    for(int i=0;i<1000;i++)
    {
        std::vector<std::function<bool(int)> > and_terms;
        auto num_inequalities = terms_dist(generator) + 1; // more usually a low integer of at least 1
        
        // and_terms will be a list of functions that test a parameter against a certain random operation and value
        std::ostringstream description;
        for(int j=0; j<num_inequalities; j++)
        {
            auto op = operation_dist(generator);
            auto val = value_dist(generator);
            description << (j?" and ":" ");
            switch(op)
            {
            case 0: description << "<" << val; break;
            case 1: description << ">" << val; break;
            case 2: description << "<=" << val; break;
            case 3: description << ">=" << val; break;
            }
            and_terms.emplace_back( [op, val](int v)
            {
                switch(op)
                {
                case 0: return v < val;
                case 1: return v > val;
                case 2: return v <= val;
                case 3: return v >= val;
                }
                return false; // unreachable
            } );
        }
        
        // perform tests on range [-11,11]
        std::map<int,bool> results;
        for(int v=-11; v<=11; v++)
        {
            results[v]=true; // assume they all passed
            for(int j=0; j<num_inequalities; j++)
                if(!and_terms[j](v))
                {
                    results[v]=false;
                    break; // short circuit
                }
            if(results[v])
                std::cout << "*";
            else
                std::cout << ".";
        }
        std::cout << description.str() << std::endl;
        
    }

  return 0;
}