Cộng 2 số nguyên ( Dùng &, ^, | )

#include <stdio.h>
#include <conio.h>

void dec2bin(int num, int a[], int *n){
    int i=0;
    while(num!=0){
        a[i++] = num % 2 ;
        num /= 2;
    }
    *n = i;
}

int bin2dec(int a[], int n){
    int i=0, lthua=1, result=0;
    for(i=0;i<=n;i++){
        result += a[i] * lthua;
        lthua *= 2;
    }
    return result;
}

int main(){
    int a[100], b[100], num1, num2, n, m, i, k;
    printf("Nhap so 1: ");
    scanf("%d",&num1);
    printf("Nhap so 2: ");
    scanf("%d",&num2);
    dec2bin(num1,a,&n);
    dec2bin(num2,b,&m);

    if(n<m){
        k = m;
        for(i=n;i<=k;i++)
            a[i]=0;
        b[i-1] = 0;
    }else
        if(n>m){
            k = n;
            for(i=m;i<=k;i++)
                b[i]=0;
            a[i-1] = 0;
        }else{
            k = m;
            a[k] = b[k] = 0;
        }
    int sum[100], carry=0;
    for(i=0;i<=k;i++){
        sum[i] = (a[i] ^ b[i] ) ^ carry;
        carry = (((a[i] ^ b[i]) & carry) | (a[i] & b[i]));
    }
    printf("\n%4d = ",num1);
    for(i=k;i>=0;i--)
        printf("%d ",a[i]);

    printf("\n%4d = ",num2);
    for(i=k;i>=0;i--)
        printf("%d ",b[i]);

    printf("\n  -----------------");
    printf("\n%4d = ",bin2dec(sum,k));
    for(i=k;i>=0;i--)
        printf("%d ",sum[i]);
    printf("\n");
}