Codeforces 1142A（性质、暴举）

队友和大佬都什么几种情况啥的……我是把终点都插了，起点随便选一个，暴举答案莽A。

 const int maxn = 1e5 + ;
 ll n, k, a, b, aa, minn = INF, maxx = -;
 set<ll> bb;

 ll gcd(ll a, ll b) {
     return b ? gcd(b, a % b) : a;
 }

 int main() {
     cin >> n >> k >> a >> b;
     ll T = n * k;
     rep(i, , n - ) {
         ll p = (ll)i * k + ;
         bb.insert((p + b) % T);
         bb.insert((p - b + T) % T);
     }
     aa = ( + a) % T;
     for(set<ll>::iterator it = bb.begin(); it != bb.end(); it++) {
         ll t = *it;
         ll ans = T / gcd(T, (t - aa + T) % T);
         minn = min(minn, ans);
         maxx = max(maxx, ans);
     }
     cout << minn << " " << maxx << endl;
     return ;
 }