C++

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

static const int max_word_count = 50;
static const int word_length = 30;

int read_in(string e[][word_length], string f[][word_length]);
void sort_words(string e[][word_length], string f[][word_length], const int used);
void search_words(const string e[][word_length], const string f[][word_length], const int used);
void write_out(const string e[][word_length], const string f[][word_length], const int used);

int main()
{
    string englishWords[max_word_count][word_length];
    string frenchWords[max_word_count][word_length];
    int num;
    num = read_in(englishWords, frenchWords);
    sort_words(englishWords, frenchWords, num);
    search_words(englishWords, frenchWords, num);
    write_out(englishWords, frenchWords, num);
    return(0);
}

int read_in(string e[][word_length], string f[][word_length])

{
    ifstream infile;
    infile.open("dict.txt");
    if(!infile)
    {
        cout<<"Error opening output file"<<endl;
        return -1;
    }

    int count = 0;
    while(count<max_word_count && infile >> e[count][word_length])
    {
        while(cin.peek()==' ')
            cin.get();
        getline(cin, f[count++][word_length]);
    }

    infile.close();
    //what do mean by return number used?
} //have warning here says "Control reaches end of non-void function"

void sort_words(string e[][word_length], string f[][word_length], const int used)
{
    for(int i = 0; i < used; i++)
    {
        for(int j = (i + 1); j < used; j++)
        {
            if(e[j][word_length] < e[i][word_length])
            {
                string temp = e[j][word_length];
                e[j][word_length] = e[i][word_length];
                e[i][word_length] = temp;
                temp = f[j][word_length];
                f[j][word_length] = f[i][word_length];
                f[i][word_length] = temp;
            }
        }
    }
}

void search_words(const string e[][word_length], const string f[][word_length], const int used)
{
    cout<<"Enter the English word you are searching for: ";
    //getline(cin, input); // have an error here
    cout<<"You entered: ";
    //not sure how to do the input properly
    //i would like to have this part clarified more

}


void write_out(const string e[][word_length], const string f[][word_length], const int used)
{
    //and i don't get what exactly to do here
}