Algorytm zamiany 2 -> U1 ->U2

#include <stdio.h>
///   https://codeforwin.org/2015/08/c-program-to-find-twos-complement-of-binary-number.html
#include <stdlib.h>
#define SIZE 8

int main()
{
    char binary[SIZE + 1];
    char U1[SIZE + 1];
    char U2[SIZE + 1];
    int i, carry=1;

    printf("Wpisz %d bit liczbe w systemie binarnym: ", SIZE);

   /// wpisz ciag 8 bitow
    gets(binary);

  /// zamiana na U1
    for(i=0; i<SIZE; i++)
    {
        if(binary[i] == '1')
            U1[i] = '0';
        else if(binary[i] == '0')
            U1[i] = '1';

    }
    U1[SIZE] = '\0';


    ///U2 = Dodaj 1 do U1

    for(i=SIZE-1; i>=0; i--)
    {
        if(U1[i] == '1' && carry == 1)
        {
            U2[i] = '0';
        }
        else if(U1[i] == '0' && carry == 1)
        {
            U2[i] = '1';
            carry = 0;
        }
        else
        {
            U2[i] = U1[i];
        }
    }
    U2[SIZE] = '\0';

    printf("Binarny = %s\n", binary);
    printf("U1 = %s\n", U1);
    printf("U2 = %s\n", U2);

    return 0;
}