SpellChecker.c

version1.cc

#include <iostream>
#include <fstream>
#include<unordered_map>
#include <string>
using namespace std;
;


vector<string> exchange_two_chars(string &s);
vector<string> add_one_char(string &s);
vector<string> remove_one_char(string &s);

string normalize(string &s) {
	s.erase(s.find_last_not_of(" \n\r\t") + 1);
	for (int i = 0; i < s.size(); i++) {
		s[i] = tolower(s[i]);
	}
	return s;
}

bool readfile(unordered_map<string, int> &dictionary, string filename, int limit = -1) {
	
	vector<string> org_words;
		
	string line;

	ifstream myfile(filename);
	if (myfile.is_open())
	{
		while (getline(myfile, line))
		{
			if (limit == 0) break;
			limit--;
			string str = normalize(line);
			
			org_words.push_back(str);
			for (string s : add_one_char(str)) {
				dictionary[s] = 1;
			}
			for (string s : remove_one_char(str)) {
				dictionary[s] = 1;
			}
			for (string s : exchange_two_chars(str)) {
				dictionary[s] = 1;
			}
		}
		for(auto word: org_words)
		{
			dictionary[word] = 0;
		}
		myfile.close();

	}

	else {
		cout << "Failed to open the file";
		return false; }

	return true;
}

vector<string> add_one_char(string &s) {
	vector<string> vect;
	string x = "";
	string y = s;

	for (int l = 0; l < s.size() + 1; l++) {
		for (int i = 0; i < 26; i++)
		{
			char ch = 'a' + i;
			string ss = x + ch + y;
			vect.push_back(ss);
		}
		x = x + y[0];
		y = y.erase(0, 1);
	}
	return vect;
}


vector<string> remove_one_char(string &s) {
	vector<string> vect;
	for (int i = 0; i < s.size(); i++) {
		string c = s;
		c.erase(i, 1);
		vect.push_back(c);
	}
	return vect;
}
vector<string> exchange_two_chars(string &s) {
	vector<string> vect;
	for (int i = 0; i < s.size() - 1; i++) {
		string c = s;
		swap(c[i], c[i + 1]);
		vect.push_back(c);
	}
	return vect;
}

void search(unordered_map<string, int> &dictionary, string &s) {
	auto itr = dictionary.find(s);
	if (itr == dictionary.end()) {
		cout << "not found" << endl;

	}
	else {
		cout << "found " << itr->second << endl;
	}

}
int main() {
	unordered_map<string, int> dictionary;
	if (!readfile(dictionary, "w.txt",1000)) exit(1);
	else {

		cout << "Dictionary Loaded" << endl;
	}
	
	string search_string;
	cin >> search_string;
	search(dictionary,search_string);
	//exchange_two_chars(search);
	/*
	if (dictionary.find(search) == dictionary.end())
		cout << "not found";
	else cout << "found";*/



	/*for (auto item : dictionary) {

		cout << item.first << " " << item.second << endl;
	}*/
}

version2.cc

#include <iostream>
#include <fstream>
#include<unordered_map>
#include <string>
using namespace std;
;


vector<string> exchange_two_chars(string &s);
vector<string> add_one_char(string &s);
vector<string> remove_one_char(string &s);

string normalize(string &s) {
	s.erase(s.find_last_not_of(" \n\r\t") + 1);
	for (int i = 0; i < s.size(); i++) {
		s[i] = tolower(s[i]);
	}
	return s;
}

bool readfile(unordered_map<string, int> &dictionary, string filename, int limit = -1) {
	int cnt = 0;
	vector<string> org_words;
		
	string line;

	ifstream myfile(filename);
	if (myfile.is_open())
	{
		while (getline(myfile, line))
		{
			if (limit == 0) break;
			limit--;
			cnt++;
			if (cnt% 10000==0)cout << ".";

			string str = normalize(line);
			
			org_words.push_back(str);
		/*	for (string s : add_one_char(str)) {
				dictionary[s] = 1;
			}*/
			for (string s : remove_one_char(str)) {
				dictionary[s] = 1;
			}
			for (string s : exchange_two_chars(str)) {
				dictionary[s] = 1;
			}
		}
		for(auto word: org_words)
		{
			dictionary[word] = 0;
		}
		myfile.close();

	}

	else {
		cout << "Failed to open the file";
		return false; }

	return true;
}

vector<string> add_one_char(string &s) {
	vector<string> vect;
	string x = "";
	string y = s;

	for (int l = 0; l < s.size() + 1; l++) {
		for (int i = 0; i < 26; i++)
		{
			char ch = 'a' + i;
			string ss = x + ch + y;
			vect.push_back(ss);
		}
		x = x + y[0];
		y = y.erase(0, 1);
	}
	return vect;
}


vector<string> remove_one_char(string &s) {
	vector<string> vect;
	for (int i = 0; i < s.size(); i++) {
		string c = s;
		c.erase(i, 1);
		vect.push_back(c);
	}
	return vect;
}
vector<string> exchange_two_chars(string &s) {
	vector<string> vect;
	for (int i = 0; i < s.size() - 1; i++) {
		string c = s;
		swap(c[i], c[i + 1]);
		vect.push_back(c);
	}
	return vect;
}

pair<string,int> search(unordered_map<string, int> &dictionary, string &s) {
	bool found = false;
	string found_string;
	int difference;
	auto itr = dictionary.find(s);
	if (itr == dictionary.end()) {
		for (string str : remove_one_char(s)) {
			cout << str << endl;
			auto it = dictionary.find(str);
			if (it != dictionary.end()) {
				found = true;
				found_string = it->first;
				difference = it->second + 1;
				break;
			}
		}
	}
	else {
		found = true;
		found_string = itr->first;
		difference = itr->second;
	}
	
	
	if (found) {
		cout << "found " << s << " " << found_string << " " << difference << endl;
		return make_pair(found_string, difference);
	}
	else
		return make_pair("NOT FOUND", -1);

}
int main() {
	unordered_map<string, int> dictionary;
	if (!readfile(dictionary, "words.txt")) exit(1);
	else {

		cout << "Dictionary Loaded" << endl;
	}

	string search_string;
	cin >> search_string;
	while (search_string != "end!") {

		search(dictionary, search_string);
		cin >> search_string;
	}
	//exchange_two_chars(search);
	/*
	if (dictionary.find(search) == dictionary.end())
		cout << "not found";
	else cout << "found";*/



	/*for (auto item : dictionary) {

		cout << item.first << " " << item.second << endl;
	}*/
}