exercise14_38.cpp

#include <iostream>
#include <string>
#include <fstream>
#include <vector>
#include <map>

struct IsInRange
{
	IsInRange(std::size_t lower, std::size_t upper)
	:_lower(lower), _upper(upper)
	{}

	bool operator()(std::string const& str) const
	{
		return str.size() >= _lower && str.size() <= _upper;
	}

	std::size_t lower_limit() const
	{
		return _lower;
	}

	std::size_t upper_limit() const
	{
		return _upper;
	}
private:
	std::size_t _lower;
	std::size_t _upper;
};

int main()
{
	//create predicates with various upper limits.
	std::size_t lower = 1;
	auto uppers = { 3u, 4u, 5u, 6u, 7u, 8u, 9u, 10u, 11u, 12u, 13u, 14u };
	std::vector<IsInRange> predicates;
	for (auto upper : uppers)
		predicates.push_back(IsInRange{ lower, upper });

	//create count_table to store counts 
	std::map<std::size_t, std::size_t> count_table;
	for (auto upper : uppers)
		count_table[upper] = 0;

	//read file and count
	std::ifstream fin("../data/storyDataFile.txt");
	for (std::string word; fin >> word; /* */)
	for (auto is_size_in_range : predicates)
	if (is_size_in_range(word))
		++count_table[is_size_in_range.upper_limit()];

	//print
	for (auto pair : count_table)
		std::cout << "count in range [1, " << pair.first << "] : " << pair.second << std::endl;

	return 0;
}