#include <cmath> #include <cstdio> #include <cstring> #include <vector> #include <algorithm> typedef long long i64; const int N = 137000 + 10, M = 100 + 10; int n, pool[M], tot; int res[N], cnt; i64 m, ans; int threshold; void dfs(int i, int cur) { if (i == tot) { res[cnt++] = cur; return; } dfs(i + 1, cur); while ((i64)cur * pool[i] <= threshold) dfs(i + 1, cur *= pool[i]); } void init() { scanf("%d%lld", &n, &m); for (int i = 0; i < n; ++i) scanf("%d", &pool[i]); std::sort(pool, pool + n); n = std::unique(pool, pool + n) - pool; tot = std::upper_bound(pool, pool + n, 25) - pool; threshold = sqrt(m) + 3; } void calc(int i, i64 cur) { if (cur > m) return; if (i == n) { int temp = *(std::upper_bound(res, res + cnt, m / cur) - 1); ans = std::max(ans, cur * temp); return; } calc(i + 1, cur); while (cur <= m / pool[i] + 1) calc(i + 1, cur *= pool[i]); } void solve() { cnt = 0; dfs(0, 1); std::sort(res, res + cnt); cnt = std::unique(res, res + cnt) - res; calc(tot, 1); } int main() { init(); solve(); std::rotate(pool, pool + tot, pool + n); tot = n - tot; solve(); printf("%lld\n", ans); return 0; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 | #include <cmath> #include <cstdio> #include <cstring> #include <vector> #include <algorithm> typedef long long i64; const int N = 137000 + 10, M = 100 + 10; int n, pool[M], tot; int res[N], cnt; i64 m, ans; int threshold; void dfs(int i, int cur) { if (i == tot) { res[cnt++] = cur; return; } dfs(i + 1, cur); while ((i64)cur * pool[i] <= threshold) dfs(i + 1, cur *= pool[i]); } void init() { scanf("%d%lld", &n, &m); for (int i = 0; i < n; ++i) scanf("%d", &pool[i]); std::sort(pool, pool + n); n = std::unique(pool, pool + n) - pool; tot = std::upper_bound(pool, pool + n, 25) - pool; threshold = sqrt(m) + 3; } void calc(int i, i64 cur) { if (cur > m) return; if (i == n) { int temp = *(std::upper_bound(res, res + cnt, m / cur) - 1); ans = std::max(ans, cur * temp); return; } calc(i + 1, cur); while (cur <= m / pool[i] + 1) calc(i + 1, cur *= pool[i]); } void solve() { cnt = 0; dfs(0, 1); std::sort(res, res + cnt); cnt = std::unique(res, res + cnt) - res; calc(tot, 1); } int main() { init(); solve(); std::rotate(pool, pool + tot, pool + n); tot = n - tot; solve(); printf("%lld\n", ans); return 0; } |