#include <fstream>
#include <iostream>
#include <cstring>

char inputString[256], outputString[256];
char encrypt[3]={'l','a', '\0'};
char vowels[7]={'a','e','y','u','i','o','\0'};
int s;
std::ofstream myfile;

void function1 (char*){
    myfile.open ("example.txt");
    std::cout << "Enter words\n";
    std::cin >> (inputString);
    myfile << inputString;
    myfile.close();
}


void function2 (char*){
    std::ifstream ("example.txt");
    myfile.open ("example.txt");
    std::cout << "Entered: " << inputString << "\n";
}

void function3 (char*, char*, char*){
    for (int i = 0; i < strlen(inputString); i++){
        char buff[256]="";
        strncpy(buff, inputString+i, 1);
        for (int j = 0; j < strlen(vowels); j++){
            if (buff[0] == vowels[j]){
                strcat(buff, encrypt);
                break;
            }
        }
        strcat(outputString, buff);
    }
    strcpy(inputString, outputString);
    std::cout << "Encrypt: " << inputString << "\n";
    myfile << inputString;
    myfile.close();
}


void function4 (char*, char*, char*, char*){
    std::ifstream("example.txt");
    myfile.open ("example.txt");

    char outputString[256]="";

    for (int i=0; i < strlen(inputString); i++){
        char buff[256] = "";
        strncpy(buff, inputString+i, 1);
        for (int j=0; j < strlen(vowels); j++){
            if (buff[0] == vowels[j]){
                char twoSymbols[256]="";
                strncpy(twoSymbols, inputString+i+1, 2);
                if (strcmp(twoSymbols, encrypt) == 0){
                    i+=2;
                    break;
                }
            }
        }
        strcat(outputString,buff);
    }

    std::cout <<"Decrypt: " << outputString;
    myfile << "Encrypted word: " <<inputString << "\n" << "Decrypted word: " << outputString;
    myfile.close();
}

void function5(){
    //exit(5);
}

int defaultFunction(){
    s=0;
    std::cout <<("Choose one of case\n");
    std::cout <<("1 = Сформировать с клавиатуры строку  и записать в файл\n");
    std::cout <<("2 = Считать строку из файла и распечатать\n");
    std::cout <<("3 = Зашифровать строку и записать в файл\n");
    std::cout <<("4 = Расшифровать строку и записать в файл\n");
    std::cout <<("5 = Exit\n");
    std::cin >> s;
    return 0;
}

int main() {

    defaultFunction();

    switch(s) {

        case 1: function1(inputString); return defaultFunction();

        case 2: function2(inputString); break;

        case 3: function3(inputString, vowels, encrypt); break;

        case 4: function4(inputString, outputString, vowels, encrypt); break;

        case 5: function5(); break;
    }
}