Overloading Operator and vector STL problems - c++

Question

I have a task: Implementing 60.000 English words from EnglishWords.txt, then Sorting it and Searching.
I have done the Sorting and Linear Search using custom MergeSort and find_if STL but when i tried to use other vector STL like upper_bound, lower_bound, binary_search it cause some problems below:
If the lower_bound function run, it does not return the same "Index" with "searchmanually" function.
Can not use "MatchString" (My overload operator) for lower_bound and binary_search ST or other vector STL and return C2672 and C2893 code.
Also, can some one give me some advices on "sorting" base on alphabetical.
My full code is on https://onlinegdb.com/l4pfS9pYJ, please click on "Fork this" to edit the code.
Some additional requirements and notions.
I'm new to OOP so show me some advices to improve my code writing skills.
Do not use STL sort(), write your own.
Must put all sorting, searching and working function to FastDictionary.
Below is my overload operator and the function that has problem.
void searchmanually(vector<Dictionary> list, string value)
{
vector<Dictionary>::iterator it;
it = find_if(list.begin(), list.end(), FastDictionary::MatchString(value));
if (it != list.end())
{
auto idx = distance(list.begin(), it);
cout << "Index = " << idx << endl;
}
else
{
cout << "Can not find the value !." << endl;
}
}
void binary_search_find_index(vector<Dictionary> list, string value)
{
vector<Dictionary>::iterator it1;
it1 = lower_bound(list.begin(), list.end(), FastDictionary::MatchString(value));
if (it1 != list.end())
{
auto idx1 = distance(list.begin(), it1);
cout << "Index = " << idx1 << endl;
}
else
{
cout << "Can not find the value !." << endl;
}
}
struct MatchString
{
private:
const std::string& s_;
public:
MatchString(const std::string& s) : s_(s) {}
bool operator()(const Dictionary& obj) const
{
return obj._word == s_;
}
friend bool operator<(const Dictionary& obj, const MatchString &str)
{
return obj._word < str.s_;
}
friend bool operator>(const Dictionary& obj, const MatchString &str)
{
return obj._word > str.s_;
}
};
Because i think that my "errors" are kinda chained so i try to described the error as much detail as possible.
Many thanks.

Answer 1

First The problem is that at your given link you have named your input file incorrectly. Note carefully your input file name in the main.cpp file is EnglishWord.txt while your actual input file name is EnglistWord.txt. Note the t at the end of the file name.
Second you should replace while (reader >> word) with:
while (std::getline(reader, word))
as i have done in the below correct example:
#include<iostream>
#include<string>
#include<vector>
#include<fstream>
#include<sstream>
#include<algorithm>
using namespace std;
class Dictionary
{
public:
string _word;
public:
string word() { return _word; }
void getword(string value) { _word=value; }
string display()
{
stringstream writer;
writer << _word << " ";
return writer.str();
}
};
class FastDictionary : public Dictionary
{
public:
void merge(std::vector<Dictionary>& list, int start, int middle, int end)
{
std::vector<Dictionary> left_vector(middle - start + 1);
std::vector<Dictionary> right_vector(end - middle);
for (int i = 0; i < left_vector.size(); ++i)
left_vector[i] = list[start + i];
for (int i = 0; i < right_vector.size(); ++i)
right_vector[i] = list[middle + 1 + i];
int left_value = 0, right_value = 0;
int currentIndex = start;
while (left_value < left_vector.size() && right_value < right_vector.size()) {
if (left_vector[left_value]._word.size() <= right_vector[right_value]._word.size()) {
list[currentIndex] = left_vector[left_value];
left_value++;
}
else {
list[currentIndex] = right_vector[right_value];
right_value++;
}
currentIndex++;
}
while (left_value < left_vector.size()) list[currentIndex++] = left_vector[left_value++];
while (right_value < right_vector.size()) list[currentIndex++] = right_vector[right_value++];
}
void mergeSort(std::vector<Dictionary>& list, int start, int end) {
if (start < end) {
int middle = (start + end) / 2;
mergeSort(list, start, middle);
mergeSort(list, middle + 1, end);
merge(list, start, middle, end);
}
}
public:
void searchmanually(vector<Dictionary> list, string value)
{
vector<Dictionary>::iterator it;
it = find_if(list.begin(), list.end(), FastDictionary::MatchString(value));
if (it != list.end())
{
auto idx = distance(list.begin(), it);
cout << "Index = " << idx << endl;
}
else
{
cout << "Can not find the value !." << endl;
}
}
void binary_search_find_index(vector<Dictionary> list, string value)
{
vector<Dictionary>::iterator it1;
it1 = lower_bound(list.begin(), list.end(), FastDictionary::MatchString(value));
if (it1 != list.end())
{
auto idx1 = distance(list.begin(), it1);
cout << "Index = " << idx1 << endl;
}
else
{
cout << "Can not find the value !." << endl;
}
}
struct MatchString
{
private:
const std::string& s_;
public:
MatchString(const std::string& s) : s_(s) {}
bool operator()(const Dictionary& obj) const
{
return obj._word == s_;
}
friend bool operator<(const Dictionary& obj, const MatchString &str)
{
return obj._word < str.s_;
}
friend bool operator>(const Dictionary& obj, const MatchString &str)
{
return obj._word > str.s_;
}
};
};
void readfile(vector<Dictionary>& list)
{
ifstream reader("EnglishWord.txt");
string word;
//reader.open(, ios::in);//no need for this
if(reader)//check the state
{
while (std::getline(reader, word))//use getline
{
std::cout<<word<<std::endl;
Dictionary newList;
newList.getword(word);
list.push_back(newList);
}
}
else
{
std::cout<<"file cannot be opened"<<std::endl;
}
}
void displayvector(vector<Dictionary>& list)
{
unsigned int size = list.size();
for (int i = 0; i < size; i++)
{
cout << list[i].display();
}
}
int main()
{
vector<Dictionary>list;
FastDictionary fd;
readfile(list);
fd.mergeSort(list, 0, list.size() - 1);
displayvector(list);
cout << endl;
cout << endl;
fd.binary_search_find_index(list, "decidedly");
cout << endl;
fd.searchmanually(list, "decidedly");
cout << endl;
return 0;
}
The output of this corrected/modified example can be seen here.