Code Số đặc biệt bằng C++

`->` Gấp ạ

/**
 *    author:  tđq
**/
#include <bits/stdc++.h>
#define task ""

using namespace std;

int a[10000005], n, k, t;
int main()
{

 //freopen(task".inp" , "r" , stdin);
 //freopen(task".out" , "w" , stdout);

 ios::sync_with_stdio(false);
 cin.tie(0);

 cin >> n >> k;
 for (int i = 1; i <= n; ++i) cin >> a[i];
 for (int i = 1; i <= n; ++i)
 {
    t = __gcd(t , a[i]);
 }
 for (int i = 2; i <= sqrt(t); ++i)
 {
    if (t % i == 0)
    {
        k = i;
        break;
    }
 }
 cout << k - k % t;
 return 0;
}

#danglam228

#include <bits/stdc++.h>
using namespace std;
long long n,k;
long long gcd(long long a, long long b) {
    while (b != 0) {
        long long t = b;
        b = a % b;
        a = t;
    }
    return a;
}

int main() {
        ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    //freopen(".INP", "r", stdin);
    //freopen(".OUT", "w", stdout);
    cin >> n >> k;
    vector<long long> a(n);
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
    }
    long long g = a[0];
    for (int i = 1; i < n; ++i) {
        g = gcd(g, a[i]);
        if (g == 1) break; 
    }
    long long l = g * (k / g);
    cout << l << endl;
    return 0;
}