大佬求助！66，7 8 9tle了可以怎么修改呢

#include<iostream>
#include<vector>
using namespace std;
bool ip(int n) {
    if (n <= 3) return n > 1;
    for (int d = 2; d * d <= n; ++d)
        if (n % d == 0) return 0;
    return 1;
}
bool hw(int b)
{
    vector<int>arr;
    while (b > 0)
    {

        int temp = b;
        arr.push_back ( temp % 10);
        b /= 10;
    }
    int ans = arr.size();
    for (int i = 0; i < ans/2; i++)
    {
        if (arr[i] != arr[ans - i - 1])
            return false;
    }
    return true;
}
int main()
{
    int a, b;
    cin >> a >> b;
    for (int i = a; i <= b; i++)
    {
        bool n = (ip(i) && hw(i));
        if (n)cout << i << endl;
    }

return 0;
}