求n的所有素数

#include <iostream>
#include <vector>
using namespace std;
int main()
{
int n;
vector<int> restore;
cin >> n;
bool flag;
for (size_t i = 2; i <= n; i++)
{
flag = true;
for (size_t j = 2; j * j <= i; j++)
{
if (i%j == 0)
{
flag = false;
break;
}
}
if (flag)
{
restore.push_back(i);
}
}
cout << n << "共有" << restore.size() << "个素数，分别为：\n";
int blank = 0;
for (const int i : restore)
{
//每打印十个数换行一次
if (blank > 0 && blank % 10 == 0)
{
cout << endl;
}
cout << i << "\t";
}

system("pause");
return 0;
}