Read and write numbers in base 2

base2_add.cpp

#include<iostream>
using namespace std;

unsigned int read_base2() {
	int n=0; char c;
	for(cin.get(c); c=='0'||c=='1'; cin.get(c)) n = (n<<1)|(c-'0');
	return n;
}

void write_base2(unsigned int n, bool first=true) {
	if (n==0 && first) cout << '0';
	if (n==0) return;
	write_base2(n>>1, false);
	cout << (n&1);
}

int main() {
	unsigned int n1 = read_base2();
	unsigned int n2 = read_base2();
	cout << n1 << " + " << n2 << " = " << n1+n2 << endl;
	write_base2(n1+n2);
}