题解 | 进制转换

//KY29 进制转换
#include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>
using namespace std;
string divide(string a)//除2操作
{
    int res=0;
    for(int i=0;i<a.size();i++)
    {
        int num=res*10+a[i]-'0';
        //cout<<num/2<<' ';
        a[i]=num/2+'0';
        res=num%2;
    }
    //cout<<"\n";
    int p=0;
    while(a[p]=='0') p++;
    return a.substr(p);//去掉前导0
}
int main()
{
    string a;
    while(cin>>a){
        vector<int>s;
        while(a.size()){
            int x=a[a.size()-1]-'0';
            s.push_back(x%2);
            //cout<<x%2<<' ';
            a=divide(a);
        }
        for(long long i=s.size()-1;i>=0;i--) cout<<s[i];
        cout<<"\n";
    }
    return 0;
}