天才之作－题解 | 进制转换

#include <iostream>
#include <vector>
using namespace std;

string divide(string origin,int x){
    string ans;
    int divider=0;
    int n=origin.size();
    for(int i=0;i<n;++i){
        int current=divider*10+(origin[i]-'0');
        ans.push_back(current/x+'0');
        divider=current/x==0?current:current%x;
    }
    int i=0;
    //去掉前导零
    while(ans.size()!=1&&ans[i]=='0')i++;
    return ans.substr(i);
}
int main(){
    string str;
    while(cin>>str){
        vector<int> ans;
        if(str.size()==1&&str[0]=='0'){
            ans.push_back(0);
        }
        while(!(str.size()==1&&str[0]=='0')){
            ans.push_back((str[str.size()-1]-'0')%2);
            str=divide(str,2);
            
        }
        for(int i=ans.size()-1;i>=0;--i){
            cout<<ans[i];
        }
        cout<<endl;
    }
    return 0;
}