169 lines
3.3 KiB
C++

/* Problem URL: https://codeforces.com/problemset/problem/1920/C */
#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;
const int MAXN = 2e5 + 1;
vvi divs(MAXN);
void pre()
{
nrep(i, 2, MAXN) {
for (int j = i; j < MAXN; j += i) {
divs[j].push_back(i);
}
}
}
#define TEST 1
void solve()
{
int n;
cin >> n;
vi a(n);
cin >> a;
vi mods(n);
int ans = 1;
repv(i, divs[n]) {
int size = n / i;
rep(j, size) {
int cur = abs(a[j] - a[j + size]);
if (cur == 0) {
cur = -1;
}
for (int k = j + size; k + size < n; k += size) {
int now = abs(a[k] - a[k + size]);
if (now == 0) {
now = -1;
}
if (cur == -1 && now != -1) {
cur = now;
continue;
}
if (cur != -1 && now != -1) {
cur = gcd(cur, now);
}
}
mods[j] = cur;
}
int prev = -1;
rep(j, size) {
if (prev == -1) {
prev = mods[j];
continue;
}
if (mods[j] == -1) {
continue;
}
prev = gcd(prev, mods[j]);
}
if (prev != 1) {
ans++;
}
}
cout << ans << '\n';
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
pre();
int t;
(TEST && cin >> t) || (t = 1);
while (t--) {
solve();
}
}