D
首先暴力找出未出现的最小正整数。可以发现在数据取极限的情况下,这个数字最大是。
观察可以得出,。
也就是说,我们所需要额外添加的数字应该是在以内的质数相乘得到。
令,想要增大答案,那么加入的数所包含的质数的幂次必须是大于对应的质数的幂次的。
于是预处理出每个质数的幂次 , (满足 并且 )。
然后跑dfs,每个质数选定一个幂次放入一个数组。最后判断,能否在次操作以内,每次操作从中选择若干个数字相乘(并且满足相乘后小于等于),并将这些数字从中删除。因为中的数字很少,每次贪心的从大往小选择即可。
由于,加个剪枝就能跑的很快。
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define int long long
#define endl '\n'
vector<int> P = { 2,3,5,7,11,13,17,19,23,29,31 };
const int inf = 1e18;
int mul(int x, int y) {
__int128_t z = __int128_t(x) * y;
if (z >= inf) return inf;
return ll(z);
}
#ifdef LOCAL
template <class... Args> void debug(const Args&... args) { ((cerr << args << ", "), ...) << '\n'; }
#define debug(args...) cerr << #args << ": ", debug(args)
#define debugsq(x) cerr << #x << ": ["; for (auto i : x) cerr << i << ' '; cerr << "]\n";
#define debugmp(x) cerr << #x << ": [ "; for (auto [i, j] : x) cerr << '[' << i << "," << j << "] "; cerr << "]\n";
#else
#define debug(...) ;
#define debugsq(...) ;
#define debugmp(...) ;
#endif
void Prework() {
}
void Solve() {
int n, x, y;cin >> n >> x >> y;
//x = 1e14;
//y = 1e14;
//y = 72201776446800 - 1;
//y = 2329089562800 - 1;
//y = 80313433200 - 1;
//y = 26771144400 - 1;
//y = 5354228880 - 1;
//y = 232792560 - 1;
//y = 12252240 - 1;
//y = 720720 - 1;
//y = 360360 - 1;
//y = 27720 - 1;
//y = 2520 - 1;
int l = 1, p = min(x, n);
for (int i = 1;i <= x && i <= n;i++) {
int nl = lcm(l, i);
if (nl > y) {
p = i - 1;
break;
}
l = nl;
}
if (p == min(x, n)) {
cout << l << endl;
return;
}
vector<int> cnt(11);
for (int i = 0;i < 11;i++) {
int aux = l;
while (aux % P[i] == 0) aux /= P[i], cnt[i]++;
}
vector<vector<array<int, 2>>> a(11);
for (int i = 0;i < 11;i++) {
int now = 1;
for (int j = 1;j <= cnt[i];j++) now = mul(now, P[i]);
int cur = 1;
while (mul(now, P[i]) <= x && mul(mul(cur, P[i]), l) <= y) {
now = mul(now, P[i]);
cur = mul(cur, P[i]);
a[i].push_back({ now,cur });
}
}
vector<int> vec;
int res = l;
auto dfs = [&](auto&& dfs, array<int, 3> att, int t) {
if (mul(att[1], l) > y) return;
if (t == 11) {
if (mul(att[1], l) <= res) return;
auto V = vec;
sort(V.begin(), V.end(), greater<int>());
int k = 0;
while (V.size()) {
vector<int> nV;
int now = 1, c = 0;
for (int i = 0;i < V.size();i++) {
if (mul(now, V[i]) <= x) now = mul(now, V[i]);
else nV.push_back(V[i]);
}
swap(V, nV);
k++;
}
//cout << att[1] << " " << l << endl;
if (k + p <= n) res = max(res, mul(att[1], l));
return;
}
dfs(dfs, att, t + 1);
for (auto [u, v] : a[t]) {
vec.push_back(u);
array<int, 3> natt = { mul(att[0],u),mul(att[1],v),att[2] + 1 };
dfs(dfs, natt, t + 1);
vec.pop_back();
}
};
dfs(dfs, { 1,1,0 }, 0);
// cout << l << " " << p << endl;
//cout << y / l << endl;
// for (auto i : a) cout << i.size() << ' ';
cout << res << endl;
}
signed main() {
ios::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
int T = 1;
cin >> T;
Prework();
while (T--) Solve();
}