文本查询TextQuery类文件

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TextQuery.h

#pragma once

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



class TextQuery
{
public:
	TextQuery(void);
	~TextQuery(void);

	typedef std::vector <std::string>::size_type line_no;

	void read_file(std::ifstream &is)
	{
		store_file(is);
		build_map();

	}

	std::string text_line(line_no) const;

	std::set<TextQuery::line_no> run_query(const std::string &query_word) const;

private:
	void store_file(std::ifstream &is);

	void build_map();

	std::vector <std::string> lines_of_text;	//line string of txt

	std::map < std::string, std::set<line_no> > word_map;
};

TextQuery.cpp

#include "TextQuery.h"


TextQuery::TextQuery(void)
{
}


TextQuery::~TextQuery(void)
{
}



void TextQuery::store_file(std::ifstream &is)
{
	std::string textline;

	while(getline(is, textline))
	{
		lines_of_text.push_back(textline);
	}
}


void TextQuery::build_map()
{
	for(line_no line_num = 0; line_num != lines_of_text.size(); ++line_num)
	{
		std::istringstream line(lines_of_text[line_num]);

		std::string word;

		while(line >> word)
		{
			word_map[word].insert(line_num);
		}
	}
}

std::set<TextQuery::line_no> TextQuery::run_query(const std::string &query_word) const
{
	std::map<std::string, std::set<line_no>>::const_iterator loc = word_map.find(query_word);

	if(loc == word_map.end())
	{
		return std::set<line_no>();
	}else
	{
		return loc->second;
	}
}

std::string TextQuery::text_line(line_no line) const
{
	if(line < lines_of_text.size())
	{
		return lines_of_text[line];
	}else
	{
		throw::std::out_of_range("line number out of range");
	}
}

　　

main.cpp

#include <iostream>
#include <algorithm>

#include "TextQuery.h"

#include <iterator>

//using namespace::std;

std::string make_plural(std::set<TextQuery::line_no>::size_type sizetemp, std::string str1, std::string str2)
{
	if(sizetemp <= 1)
	{
		return str1;
	}else
	{
		return str1 + str2;
	}
}

void print_results(const std::set<TextQuery::line_no> &locs, 
								const std::string &sought, const TextQuery &file)
{
	typedef std::set<TextQuery::line_no> line_nums;

	line_nums::size_type size = locs.size();

	std::cout << "\n" << sought << " occurs " << size << " " << make_plural(size, "time", "s") << std::endl;

	line_nums::const_iterator it = locs.begin();

	for(; it != locs.end(); ++it)
	{
		std::cout << "\t(line " << (*it) +1 << ") " << file.text_line(*it) << std::endl;
	}
}

std::ifstream& open_file(std::ifstream &in, const std::string &file)
{
	in.close();
	in.clear();
	in.open(file.c_str());
	return in;
}




int main(int argc, char* argv[])
{

	std::ifstream infile;

	if(/*argc < 2 ||*/ !open_file(infile, "D:\\TEXT.txt"))
	{
		std::cerr << "No input file!" << std::endl;

		return EXIT_FAILURE;
	}

	TextQuery tq;

	tq.read_file(infile);

	while(true)
	{
		std::cout << "enter word to look for, or q to quit: ";
		std::string s;
		std::cin >> s;

		if(!std::cin || s == "q") break;

		std::set<TextQuery::line_no> locs = tq.run_query(s);

		print_results(locs, s, tq);
	}
	

	return 0;
}