What does this code do?

[Badshah]

#include<stdio.h>

typedef char bit;
bit carry = 0;
bit halfadd( bit A, bit B )
{
    carry = A & B;
    return A ^ B;
}
bit fulladd( bit A, bit B )
{
    bit xor = A ^ B;
    bit ret = carry ^ xor;
    carry = (carry & xor) | (A & B);
    return ret; 
}

void fillNum( int num, bit *array )
{
    int i;
    for( i = 0; i < 32; ++ i ){
        array[i] = ( num >> i ) & 1;
    }
}

int main()
{ 
    bit num1[32] = {0}, num2[32] = {0};
    int A = 220, B = 224;
    fillNum( A, num1 );
    fillNum( B, num2 );

    int r = 0;
    bit tmp = halfadd( num1[0], num2[0] );
    putchar( tmp ? '1' : '0' );
    r = tmp;
    int i;
    for( i = 1; i < 32; ++i )
	{
        tmp = fulladd( num1[i], num2[i] );
        r += tmp << i;
        putchar( tmp ? '1' : '0' );
    }
    putchar( carry ? '1' : '0' );
    printf("\n%d\n\n%d + %d = %d", r, A, B, A+B);
    return 0;
}

[JeremyLT]

Can you give us more context? Where did you find this? What have you tried to do to understand it? It looks like it is doing arithmetic with bitwise operations.

[Badshah]

Out teacher gave us task “An ALU has 4bit adder (+), discuss how two
8bit integers can be added (+). Give
example in C Program”
I got this program online but do not know how it works. i need it to prepare for viva please help me to understand this code

[JeremyLT]

Well, lets back up. What do you understand about adding 4 or 8 bit integers?

[Badshah]

No i don’t
I just want to understand this code if you can help me with by explaining the whole code it will be helpful for me

[JeremyLT]

If you are just interested in getting someone else’s code to work for you, then this question isn’t the sort I get excited about answering. I’ll let someone else answer.

[Badshah]

Please if you know how this code works then please help me