#include<bits/stdc++.h> using namespace std; # ifdef DEB # define debug(...) fprintf(stderr, __VA_ARGS__) # else # define debug(...) #endif #define F first #define S second #define MP make_pair #define PB push_back #define LL long long #define LD long double #define PII pair<int, int> #define PLL pair<LL, LL> #define pb pop_back #define VI vector<int> #define VPI vector<PII> #define FOR(i,a,b) for(int i = (a); i <= (b); i++) #define FORD(i,a,b) for(int i = (a); i >= (b); i--) #define RE(i,n) FOR(i,1,n) #define REP(i,n) FOR(i,0,(int)(n)-1) #define ALL(x) (x).begin(), (x).end() #define siz(V) ((int)V.size()) const LL inf = 3.5e8; const int M = 1.8e6; vector<int> P; int V[M]; LL res = 1, n, k, inf2, r; int len = 0; void generate1(LL x, int ind) { if (ind >= siz(P)) { V[len++] = x; return; } while (x <= inf) { generate1(x, ind + 1); x *= P[ind]; } } void check(LL x) { int st = 0, en = len - 1, mid = (st + en) / 2; while (st <= en) { if (x <= k / V[mid]) { res = max(res, x * V[mid]); st = mid + 1; } else { en = mid - 1; } mid = (st + en) / 2; } } void generate2(LL x, int ind, int mini) { if (ind >= siz(P)) { if (x >= inf2 - 1000) { check(x); } return; } generate2(x, ind + 1, mini); mini = min(mini, P[ind]); x *= P[ind]; while (x <= inf2 * mini) { generate2(x, ind + 1, mini); x *= P[ind]; } } int main() { //ios_base::sync_with_stdio(0); scanf("%lld%lld", &n, &k); for (int i = 0; i < n; i++) { LL a; scanf("%lld", &a); P.PB(a); } sort(ALL(P)); reverse(ALL(P)); generate1(1, 0); sort(V, V + len); inf2 = max(1LL, (k + inf - 1) / inf); generate2(1, 0, inf); printf("%lld\n", res); 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 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 | #include<bits/stdc++.h> using namespace std; # ifdef DEB # define debug(...) fprintf(stderr, __VA_ARGS__) # else # define debug(...) #endif #define F first #define S second #define MP make_pair #define PB push_back #define LL long long #define LD long double #define PII pair<int, int> #define PLL pair<LL, LL> #define pb pop_back #define VI vector<int> #define VPI vector<PII> #define FOR(i,a,b) for(int i = (a); i <= (b); i++) #define FORD(i,a,b) for(int i = (a); i >= (b); i--) #define RE(i,n) FOR(i,1,n) #define REP(i,n) FOR(i,0,(int)(n)-1) #define ALL(x) (x).begin(), (x).end() #define siz(V) ((int)V.size()) const LL inf = 3.5e8; const int M = 1.8e6; vector<int> P; int V[M]; LL res = 1, n, k, inf2, r; int len = 0; void generate1(LL x, int ind) { if (ind >= siz(P)) { V[len++] = x; return; } while (x <= inf) { generate1(x, ind + 1); x *= P[ind]; } } void check(LL x) { int st = 0, en = len - 1, mid = (st + en) / 2; while (st <= en) { if (x <= k / V[mid]) { res = max(res, x * V[mid]); st = mid + 1; } else { en = mid - 1; } mid = (st + en) / 2; } } void generate2(LL x, int ind, int mini) { if (ind >= siz(P)) { if (x >= inf2 - 1000) { check(x); } return; } generate2(x, ind + 1, mini); mini = min(mini, P[ind]); x *= P[ind]; while (x <= inf2 * mini) { generate2(x, ind + 1, mini); x *= P[ind]; } } int main() { //ios_base::sync_with_stdio(0); scanf("%lld%lld", &n, &k); for (int i = 0; i < n; i++) { LL a; scanf("%lld", &a); P.PB(a); } sort(ALL(P)); reverse(ALL(P)); generate1(1, 0); sort(V, V + len); inf2 = max(1LL, (k + inf - 1) / inf); generate2(1, 0, inf); printf("%lld\n", res); return 0; } |