akinator 2.1

#include <iostream>
#include <cstdio>
#include <malloc.h>
#include <assert.h>
#include <stdlib.h>

using namespace std;

FILE* open_tree();
void goto_yes_block(FILE* file);
void goto_no_block(FILE* file);
int show_message(FILE* file);
void ask_question(FILE* file);
void add_new_block(FILE* file);
void go_back_while(char c , FILE* file);
void who_is_it(char** pman , char** pdifferent , char** pwrong_man , FILE* file);
void am_i_right(FILE* file);
int want_to_continue();

const char name_of_file[] = "data.txt";
const char base_line[] = "man(old(prut)(anicin))(old(lunina)(markasheva))";

int main()
{
    FILE* file = open_tree();
    int cont = 0;
    do
    {
        if (system("clear")) system( "cls" );
        ask_question(file);
        am_i_right(file);
        cont = want_to_continue();
    }while(cont);


    fclose(file);
    return 0;
}


FILE* open_tree()
{
    FILE* file = fopen(name_of_file , "r+");
    char ans;
    if(!file)
    {
        printf("CAN'T OPEN %s! Do you want to create it?(y/n) " , name_of_file);
        ans = getchar();
        getchar();
        if(ans == 'y')
        {
            file = fopen(name_of_file , "w");
            fprintf(file , "%s" , base_line);
            fclose(file);
            file = fopen(name_of_file , "r+");
        }
        else
            exit(0);
    }
    rewind(file);
    return file;
}

void goto_yes_block(FILE* file)
{
    fseek(file , 1 , SEEK_CUR);
    return;
}

void goto_no_block(FILE* file)
{
    int c = 0;
    int open_closed = 1;
    fseek(file , 1 , SEEK_CUR);
    while(open_closed != 0)
    {
        c = fgetc(file);
        if(c == '(')
            open_closed++;
        if(c == ')')
            open_closed--;
    }
    fseek(file , 1 , SEEK_CUR);
    return;
}

int show_message(FILE* file)
{
    char* message;
    fscanf(file , "%m[^(^)]" , &message);
    int c = fgetc(file);
    ungetc(c , file);
    if(c == '(')
    {
        printf("%s?(y/n) " , message);
        free(message);
        return 1;
    }
    else
    {
        printf("It is %s" , message);
        free(message);
        return 0;
    }

}

void ask_question(FILE* file)
{
    rewind(file);
    int is_question = 1;
    char ans = 0;
    is_question = show_message(file);
    while(is_question)
    {
        ans = getchar();
        getchar();
        if(ans == 'y')
            goto_yes_block(file);
        else
            goto_no_block(file);

        is_question = show_message(file);
    }
    return;
}

void add_new_block(FILE* file)
{
    char* man , * different , * wrong_man;
    who_is_it(&man , &different , &wrong_man , file);

    fpos_t pos;
    fgetpos(file , &pos); //man(old(bec|)(anicin))(old(lunina)(markasheva))

    char* end_part;
    fscanf(file , "%ms" , &end_part); // )(anicin))(old(lunina)(markasheva))

    fsetpos(file , &pos); //man(old(bec|)(anicin))(old(lunina)(markasheva))
    fseek(file , 1 , SEEK_CUR);  //man(old(bec)|(anicin))(old(lunina)(markasheva))

    fprintf(file , "(%s)\n" , man);       //man(old(bec)(chubarov)|
    go_back_while(')' , file);                   //man(old(bec)(chubarov|)
    go_back_while('(' , file);                   //man(old(bec)|(chubarov)
    go_back_while(')' , file);                   //man(old(bec|)(chubarov)
    go_back_while('(' , file);                   //man(old|(bec)(chubarov)

    char* middle_part;
    fscanf(file , "%m[^\n]" , &middle_part);     // (bec)(chubarov)
                                          //man(old(bec)(chubarov)|
    go_back_while(')' , file);                   //man(old(bec)(chubarov|)
    go_back_while('(' , file);                   //man(old(bec)|(chubarov)
    go_back_while(')' , file);                   //man(old(bec|)(chubarov)
    go_back_while('(' , file);                   //man(old|(bec)(chubarov)
    fseek(file , 1 , SEEK_CUR);           //man(old(|bec)(chubarov)

    fprintf(file , "%s" , different);     //man(old(likes_vans|rov)
    fprintf(file , "%s" , middle_part);   //man(old(likes_vans(bec)(chubarov)|
    fprintf(file , "%s" , end_part);      //man(old(likes_vans(bec)(chubarov))(anicin))(old(lunina)(markasheva))|

    free(end_part);
    free(middle_part);
    free(wrong_man);
    free(man);
    free(different);


}

void go_back_while(char c , FILE* file)
{
    char cur = 0;
    int res = 0;
    while(cur != c)
    {
        res = fseek(file , -1 , SEEK_CUR);
        assert(!res);
        cur = fgetc(file);
        res = fseek(file , -1 , SEEK_CUR);
        assert(!res);
    }
    return;
}

void who_is_it( char** pman , char** pdifferent , char** pwrong_man , FILE* file)
{
    go_back_while('(' , file);         //man(old|(bec)(anicin))(old(lunina)(markasheva))
    fseek(file , 1 , SEEK_CUR); //man(old(|bec)(anicin))(old(lunina)(markasheva))
    fscanf(file , "%m[^')']" , pwrong_man); //man(old(bec|)(anicin))(old(lunina)(markasheva))
    assert(*pwrong_man);

    do
    {
        printf("Who is it?\n");
        scanf("%m[^\n]" , pman);
        getchar();
    }while(!*pman);

    do
    {
        printf("What %s differs from %s?\n" , *pwrong_man , *pman);
        scanf("%m[^\n]" , pdifferent);
        getchar();
    }while(!*pdifferent);

    return;
}

void am_i_right(FILE* file)
{
    printf(" Am I right?(y/n) ");
    char ans;
    ans = getchar();
    getchar();
    if(ans == 'y')
    {
        printf("I know it! ");
        return;
    }
    else
    {
        printf("Do you want to add this person?(y/n) ");
        ans = getchar();
        getchar();
        if(ans == 'y')
            add_new_block(file);
        return;
    }

}

int want_to_continue()
{
    char ans = 0;
    printf("Do you want to continue?(y/n) ");
    ans = getchar();
    getchar();
    if(ans == 'y')
        return 1;
    else
        return 0;
}