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#include <iostream>
#include <set>
#include <fstream>
#include <cmath>

using namespace std;

string intTobin(int code){
    if(code == 0) return "0";
    string ch = "";
    int temp = code;
    while(temp > 0){
        ch = temp%2?"1"+ch:"0"+ch;
        temp = temp/2;
    }
    return ch;
}

int binToInt(string code){
    int result = 0;
    for(int i = 0; i < code.size(); i++){
        if(code[i] == '1'){
            result+= pow(2,code.size()-1-i);
        }
    }
    return result;
}

string intTobint(int code){
    if(code == 0) return "";
    if(code == 1) return "";
    string ch = "";
    int temp = code;
    while(temp > 0){
        ch = temp%2?"1"+ch:"0"+ch;
        temp = temp/2;
    }
    ch.erase(0,1);
    return ch;
}

string f0_code(int x){
    string result = "";
    for (int i = 0; i < x; ++i) {
        result += "0";
    }
    return result+="1";
}

string f1_code(int x){
    string result = "";
    if(x == 0) return "1";
    result = f0_code(intTobin(x).size()) + intTobint(x);
    return result;
}

string f1_decode(string code){
    string decodeResult = "";
    int skip = 0;
    int nullCount = 0;
    for(int i = 0; i < code.size(); i++){
        if (code[i] == '1'){
            if(nullCount == 0) {
                decodeResult += "0";
                if(i < code.size() - 1) decodeResult += " ";
                continue;
            }
            decodeResult += to_string(binToInt(code.substr(i,nullCount)));
            skip = nullCount-1;
            nullCount = 0;
            i+=skip;
            if(i < code.size() - 1) decodeResult += " ";
        }else{
            nullCount++;
        }
    }
    return decodeResult;
}

set<char> readAlphabet(string fileName){
    set<char> s;
    ifstream fin;
    fin.open(fileName);
    if(!fin.is_open()){
        cout << "Error open file";
    }else{
        while(!fin.eof())
            s.insert(fin.get());
    }
    fin.close();
    return s;
}

int findIndexOfArray(int* arrayAlphabet, int sizeArray ,int charByte){
    int result = -100;
    for(int i = 0; i < sizeArray; i++){
        if(charByte == arrayAlphabet[i]){
            result = i;
            break;
        }
    }
    return result;
}


void shiftElementOfArray(int* arrayAlphabet, int sizeArray , int index){
    int temp = arrayAlphabet[index];
    for(int i = index; i > 0 ; --i){
        arrayAlphabet[i] = arrayAlphabet[i-1];
    }
    arrayAlphabet[0] = temp;
}

string stackBook(string fileName, int* arrayAlphabet, int sizeArray){
    int byte;
    string result = "";
    ifstream fin;
    fin.open(fileName);
    if(!fin.is_open()){
        cout << "Error open file";
    }else{
        while(!fin.eof()){
            byte = fin.get();
            cout<<byte <<" = ";
            cout<<findIndexOfArray(arrayAlphabet, sizeArray, byte)<<endl;
            result += f1_code(findIndexOfArray(arrayAlphabet, sizeArray, byte));
            shiftElementOfArray(arrayAlphabet, sizeArray, findIndexOfArray(arrayAlphabet, sizeArray, byte));
        }
    }
    fin.close();
    return result;
}

string stackBookDecode(string bookCode, int* arrayAlphabet, int sizeArray){
    string result = "";
    string scaned = "";
    for(int i; i < bookCode.size(); i++){
        if(bookCode[i] == ' '){
            result += arrayAlphabet[stoi(scaned)];
            shiftElementOfArray(arrayAlphabet, sizeArray, stoi(scaned));
            scaned = "";

        }else{
            scaned += bookCode[i];
        }
    }
    return result;
}

int weightBitOfFile(string fileName){
    int result = 0;
    ifstream fin;
    fin.open(fileName);
    if(!fin.is_open()){
        cout << "Error open file";
    }else{
        while(!fin.eof()){
            if(fin.get() == '\n'){
                result+=2;
            }else{
                result++;
            }
        }
    }
    fin.close();
    return (result-1) * 8;
}


int main() {
    int* arrayAlphabet;
    string bookCode = "";
    string filename = "../test.txt";
    set<char> Alphabet = readAlphabet(filename);
    int sizeArray = Alphabet.size();

    arrayAlphabet = new int[sizeArray];

    set<char>::iterator setIt = Alphabet.begin();
    for(int i = 0; i < sizeArray; i++, setIt++){
        arrayAlphabet[i] = *setIt;
    }

    bookCode = stackBook(filename, arrayAlphabet, sizeArray);
    cout<<endl;
    cout<<"Text into F1Code : \n"<<bookCode<<endl<<endl;

    setIt = Alphabet.begin();
    for(int i = 0; i < sizeArray; i++, setIt++){
        arrayAlphabet[i] = *setIt;
    }

    int bitCountCode = bookCode.size();
    int bitCountFile = weightBitOfFile(filename);

    cout<<"Restored text : \n"<< stackBookDecode(f1_decode(bookCode), arrayAlphabet, sizeArray) <<endl;
    cout<<endl;
    cout<<"Size StackBook = "<<sizeArray<<endl;
    cout<<"Bits in Code = "<< bitCountCode << ", Bits in File = " << bitCountFile <<endl;
    cout<<"Compression ratio "<<(float)bitCountFile/bitCountCode<<endl;

    return 0;
}