我的代码哪有问题

#include <bits/stdc++.h>
using namespace std;
string zhuan(long long num){
	string x="";
	while(num > 0){
		x = char(num%2+'0') + x;
		num /= 2;
	}
	return x;
}
string zhuan2(string num){
	string x="";
	while(num.size() > 7){
		x = '1' + num.substr(num.size()-7,7) + x;
		num.erase(num.size()-7,7);
	}
	int len = 7 - num.size();
	for(int i=0;i<=len;i++){
		num = '0' + num;
	}
	x = x + num;
	return x; 
}
void zhuan3(string num){
	string x="";
	int temp;
	string ans="0123456789ABCDEF";
	int flag=1;
	while(num.size() != 0){
		x = num.substr(0,4);
		num.erase(0,4);
		temp = (x[0]-'0')*8 + (x[1]-'0')*4 + (x[2]-'0')*2 + (x[3]-'0')*1;
		if(flag % 2 == 0){
			cout << ans[temp] << " ";
		}
		else{
			cout << ans[temp];
		}
		flag++;
	}
}
int main(){
	long long n;
	cin >> n;
	string z =zhuan(n);
	z = zhuan2(z);
	zhuan3(z);
	return 0;
}