#include <stdio.h>
#include <string.h>
#include <stdlib.h>


struct compl
{
    int x;
    int y;
};

void text_menu()
{
    printf("Write '0' to exit\n");
    printf("Write '1' to input new complex number\n");
    printf("Write '2' to write complex number in algebraic form\n");
    printf("Write '3' to write complex number in exponential form\n");
    printf("Write '4' to write conjugate complex number\n");
    printf("Write '5' to power the number\n");
    printf("Write '6' to write information about an authorn\n");
    printf("Write '7' to write complex number in exponential form\n");
}
void check_menu_char(int *menu_pointer)
{
    char char_point[3];
    if ((char_point[0] = getchar()) != '\n') {
        if ((char_point[1] = getchar()) != '\n') {
            while (char_point[2] != '\n') {
                char_point[2] = getchar();
                *menu_pointer = -1;
            }
        }
        else {
            if (char_point[0] <= '5' && char_point[0] >= '0') {
                *menu_pointer = atoi(&char_point[0]);
            }
            else {
                *menu_pointer = -1;
            }
        }

    }
    else {
        *menu_pointer = -1;
    }
}

void write_compl_number(struct compl *compl_pointer) {
    if (0 > compl_pointer->y) {
        printf("%d%d*i\n", compl_pointer->x, compl_pointer->y);
    }
    else if (0 < compl_pointer->y){
        printf("%d+%d*i\n", compl_pointer->x, compl_pointer->y);
    }
    else {
        printf("%d\n", compl_pointer->x);

    }
}

void scan_compl_part (int *z, int *menu_pointer) {
    char input_char;
    int check_negative = 0;

    printf("Form of input of number is 'a+b*i'\n");
    printf("Please, input the natural number\n");

    input_char = getchar();

    if (input_char == '-') {
        check_negative = 1;
    }
    else if (input_char == '\n') {
        z = 0;
    }
    else {
        while (input_char != '\n') {
            if (check_negative == 1) {
                input_char = getchar();
            }
            if (input_char < '0' || input_char > '9') {
                *menu_pointer = -1;
                z = 0;
                break;
            }
            else {
                if (input_char != 'n') {
                    z = z * 10 + atoi(&input_char);
                    input_char = getchar();
                }
            }
        }
    }
    if (check_negative == 1) {
        z = -z;
    }
}


void write_conj_number(struct compl *compl_pointer) {
    int x;
    int y;

    x = compl_pointer->x;
    y = compl_pointer->y;

    if (y < 0) {
        printf("%d%d*i\n", x, y);
    }
    else if (y == 0) {
        printf("It is not a complex number. Please, try to input complex number again\n");
    }
    else {
        printf("%d+%d*i\n", x, y);
    }
}

void compl_power(struct compl *compl_pointer) {
    int x;
    int y;
    int power;

    x = compl_pointer->x;
    y = compl_pointer->y;

    printf("Please< input the power of a number\n");
    scanf("%d\n", &power);

    for (int i = 0; i < power; i++) {
        x = x * x - y * y;
        y = x * y + x * y;
    }

    printf("The powered number:  ");
    printf ("%d+%d*i\n", x, y);
}

int main() {
    struct compl compl_num;
    int menu_pointer;

    compl_num.x = 0;
    compl_num.y = 0;

    text_menu();


    do {
        printf("Input the number please ");

        check_menu_char(&menu_pointer);

        switch (menu_pointer) {
        case 1:
            scan_compl_part(&compl_num.x, &menu_pointer);
            scan_compl_part(&compl_num.y, &menu_pointer);
            break;
        case 2:
            write_compl_number(&compl_num);
            break;
        case 3:
            // write_exp_form(&compl_num);
            break;
        case 4:
            write_conj_number(&compl_num);
            break;
        case 5:
            compl_power(&compl_num);
            break;
        default:
            printf("Please, try again\n");
            break;
        }
    }while (menu_pointer != 0);

    return 0;

}