Codeforces-solutions/Codeforces Round 1089 (Div. 2)/C2. A Simple GCD Problem (Hard Version).cpp

/* Problem URL: https://codeforces.com/contest/2210/problem/C2 */

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template <class T, class comp = less<>>
using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;

#define V vector

#define rmin(a, b) a = min(a, b)
#define rmax(a, b) a = max(a, b)

#define rep(i, lim) for (int i = 0; i < (lim); i++)
#define nrep(i, s, lim) for (int i = s; i < (lim); i++)

#define repv(i, v) for (auto &i : (v))
#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
#define sortv(v) sort(v.begin(), v.end())
#define all(v) (v).begin(), (v).end()

using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vvvvi = vector<vvvi>;

using ll = long long;

using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vvvvl = vector<vvvl>;

template<class v>
auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
    os << vec[0];
    for (size_t i = 1; i < vec.size(); i++) {
        os << ' ' << vec[i];
    }
    os << '\n';
    return os;
}

template<class v>
auto operator>>(istream &is, vector<v> &vec)->istream& {
    for (auto &i : vec) {
        is >> i;
    }
    return is;
}

template<class v>
auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
    for (auto &i : vec) {
        os << i[0];
        for (size_t j = 1; j < i.size(); j++) {
            os << ' ' << i[j];
        }
        os << '\n';
    }
    return os;
}

template<class v>
auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
    for (auto &i : vec) {
        for (auto &j : i) {
            is >> j;
        }
    }
    return is;
}

const int oo = INT32_MAX >> 1;
const ll OO = INT64_MAX >> 1;

constexpr int MAXN = 5e4 + 10;
int di[MAXN];
vi divs[MAXN];
vi primes;

void pre()
{
    // fill(di, di + MAXN, 1);
    // iota(di, di + MAXN, 0);
    // primes.push_back(1);
    // nrep(i, 2, MAXN) {
    //     if (di[i] != i) {
    //         continue;
    //     }
    //     primes.push_back(i);
    //
    //     for (int j = i; j < MAXN; j += i) {
    //         di[j] = i;
    //     }
    // }

    // nrep(i, 2, MAXN) {
    //     int cur = i;
    //     while (cur > 1) {
    //         int now = di[i];
    //         divs[i].push_back(now);
    //         while (di[i] == now) {
    //             i /= now;
    //         }
    //     }
    // }
}

#define TEST 1

void solve()
{
    int n;
    cin >> n;
    vl a(n);
    vl b(n);
    cin >> a >> b;

    // vl act(n);
    // act[0] = gcd(a[0], a[1]);
    // act[n - 1] = gcd(a[n - 1], a[n - 2]);
    //
    // nrep(i, 1, n - 1) {
    //     ll g1 = gcd(a[i], a[i + 1]);
    //     ll g2 = gcd(a[i], a[i - 1]);
    //
    //     act[i] = lcm(g1, g2);
    // }
    //
    priority_queue<pair<int, int>> pq;
    rep(i, n) {
        pq.emplace(b[i], i);
    }

    int act = 0;

    // ll t = gcd(a[0], a[1]);
    // if (t != a[0] && t <= b[0]) {
    //     a[0] = t;
    //     act++;
    // }
    // t = gcd(a[n - 1], a[n - 2]);
    // if (t != a[n - 1] && t <= b[n - 1]) {
    //     a[n - 1] = t;
    //     act++;
    // }

    while (!pq.empty()) {
        auto [bi, i] = pq.top();
        pq.pop();

        ll g1 = i == n - 1 ?  1 : gcd(a[i], a[i + 1]);
        ll g2 = i == 0 ? 1 : gcd(a[i], a[i - 1]);
        ll bs = lcm(g1, g2);

        int low = 1;
        int high = 1e9;
        int ans = 0;
        while (low <= high) {
            int mid = (low + high) >> 1;

            if (bs * mid <= b[i]) {
                ans = mid;
                low = mid + 1;
                continue;
            }

            high = mid - 1;
        }

        if (ans == 0) {
            continue;
        }

        ll t1 = i == n - 1 ? 1 : a[i + 1] / g1;
        ll t2 = i == 0 ? 1 : a[i - 1] / g2;
        // ll lc = lcm(t1, t2);

        // while (ans > 0 && (t1 % primes[ans] == 0 || t2 % primes[ans] == 0 || primes[ans] * bs == a[i])) {
        //     ans--;
        // }

        if (ans % t1 == 0) {
            ans /= t1;
        }

        if (ans % t2 == 0) {
            ans /= t2;
        }

        act += bs * ans != a[i];
        a[i] = bs * ans;
    }

    cout << act << '\n';
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    pre();

    int t;
    (TEST && cin >> t) || (t = 1);
    while (t--) {
        solve();
    }
}