题解 | #进制转换#

#include <iostream>
#include <string>
#include <algorithm>
using namespace std;


void divide2(string s, string& res, int& remain)
{
    res.clear();
    int local = 0;
    for (int i = 0; i < s.length(); i++) {
        local = local * 10 + s[i] - '0';
        if (local < 2) { //到这里，不能除
            if(!res.empty())
                res = res + '0';//上0
        }
        else {
            res = res + to_string(local / 2);
            local = local % 2;
        }
    }
    remain = local;
}

int main()
{
    // 模拟除2取余法
    string s;
    string out;
    string res;
    int remain;
 
        cin >> s;

        while (true) {
            divide2(s, res, remain);
            out = to_string(remain) + out;
            if (res == "")
                break;
            s = res;

        }
        cout << out << endl;
        out.clear();
    
}