求助代码本地测试结果正确，但是提交得0分，请好心大佬帮忙看看

#include <bits/stdc++.h>
using namespace std;

unsigned long long n; 
int a[210] = {0}, l = 0, i = 0, c[100], sum, w;
string s, b, ans;

int main(){
	cin >> n;
	if(n == 0){
		cout << "00";
		return 0;
	}
	while(n){
		int sum = n % 2;
		a[++l] = sum;
		n /= 2;	
	}
	while(i * 7 <= l){
		i++;
		for(int j = 1; j <= 7; j++){
			s += a[(i - 1) * 7 + j] + '0';
		}
		if(i * 7 < l){
			s += '1';
		}
		else{
			s += '0';
		}
		for(int j = s.size() - 1; j >= 0; j--){
			b += s[j];
		}
		for(int j = 0; j < b.size(); j++){
			c[j] = b[j] - '0';
		}
		sum = 0;
		w = 1;
		for(int j = b.size() - 1; j >= 0; j--){
			sum += c[j] * w;
			w *= 2;
		} 

		int w = sum;
		while(w){
			int sum = w % 16;
			if(sum >= 10){
				ans += sum + 55;		
			}
			else{
				ans += sum + 48;
			}
			w /= 16;	
		}
		if(ans.size() == 1){
			cout << "0";
		}
		for(int j = ans.size(); j >= 0; j--){
			cout << ans[j];
		}
		cout << " ";
		ans = "";
		b = "";
		s = "";
	}
	return 0;
}