模拟求优化，若思路有误，期望改正。

#include <iostream>
#include <algorithm>
using namespace std;
string change(int x) {
	string res = "";
	while (x) {
		string p = to_string(x%2);
		res += p;
		x >>= 1;
	}
	reverse(res.begin(), res.end());
	return res;
}
string pl(string a, string b) {
	reverse(a.begin(), a.end()), reverse(b.begin(), b.end());
	int i = 0, j = 0, jw = 0;
	string ans = "";
	while (i<a.size() || j<b.size() || jw) {
		int ii = i<a.size() ? a[i]-'0' : 0, jj = j<b.size() ? b[j]-'0' : 0;
		int s = ii+jj+jw;
		jw = s>>1;
		ans += s%2 + '0';
		++i, ++j;
	}
	reverse(ans.begin(), ans.end());
	return ans;
}
int main() {
	int t;
	scanf("%d", &t);
	while (t--) {
		int n;
		scanf("%d", &n);
		string s = "";
		while (n--) {
			int op;
			scanf("%d", &op);
			if (op == 1) s += "0";
			else {
				int d;
				scanf("%d", &d);
				string str = change(d);
				s = pl(s, str);
			}
		}
		cout << s << endl;
	}
	return 0;
}