/******************************************************************************

                            Online C Compiler.
                Code, Compile, Run and Debug C program online.
Write your code in this editor and press "Run" button to compile and execute it.

*******************************************************************************/

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

struct RezultatSabiraca {
    int zbir;
    int prenos;
};

int AND(int a, int b) {
    
    if (a == 0 || b == 0) {
        return 0;
    } else {
        return 1;
    }
}
struct RezultatSabiraca sabirac(int x, int y) {
    
    struct RezultatSabiraca rezultat;
    if (x == 0 && y == 0) {
        rezultat.zbir = 0;
        rezultat.prenos = 0;
    } else if (x == 0 && y == 1) {
        rezultat.zbir = 1;
        rezultat.prenos = 0;
    } else if (x == 1 && y == 0) {
        rezultat.zbir = 1;
        rezultat.prenos = 0;
    } else {
        rezultat.zbir = 0;
        rezultat.prenos = 1;
    }
    
    return rezultat;
}

struct RezultatSabiraca potpuni_sabirac(int x, int y, int p) {
    struct RezultatSabiraca rez;
    
    if (x == 0 && y == 0 && p == 0) {
        rez.zbir = 0;
        rez.prenos = 0;    
    } else if (x == 0 && y == 0 && p == 1) {
        rez.zbir = 1;
        rez.prenos = 0;
    } else if (x == 0 && y == 1 && p == 0) {
        rez.zbir = 1;
        rez.prenos = 0;
    } else if (x == 0 && y == 1 && p == 1) {
        rez.zbir = 0;
        rez.prenos = 1;
    } else if (x == 1 && y == 0 && p == 0) {
        rez.zbir = 1;
        rez.prenos = 0;
    } else if (x == 1 && y == 0 && p == 1) {
        rez.zbir = 0;
        rez.prenos = 1;
    } else if (x == 1 && y == 1 && p == 0) {
        rez.zbir = 0;
        rez.prenos = 1;
    } else {
        rez.zbir = 1;
        rez.prenos = 1;
    }
    
    return rez;
    
}

int* paralelni_sabirac(int* x, int* y) {
    
    struct RezultatSabiraca temp;
    int* z = (int*) malloc (4*sizeof(int));
    int i;
    int prenos = 0;
    
    for (i = 3; i >= 0; i--) {
        temp = potpuni_sabirac(x[i], y[i], prenos);
        
        z[i] = temp.zbir;
        prenos = temp.prenos;
    }
    if (prenos == 1) {
        return NULL;
    } else {
        return z;
    }
}

int main()
{
    int i, j;
    int x[4]; x[0] = 0; x[1] = 0; x[2] = 0; x[3] = 0;
    for (i = 0; i < 4; i++) {
        printf("%d ", x[i]);
    }
    printf("\n");
    
    int y[4]; y[0] = 0; y[1] = 0; y[2] = 0; y[3] = 1;
   
    
    for(i = 0; i < 16; i++) {
        
        int* z = paralelni_sabirac(x, y);
        for (j = 0; j < 4; j++) {
            printf("%d ", z[j]);
            x[j] = z[j];
        }
        printf("\n");
        
    }
    
    return 0;
}