//PRZEMYSL ASSERTY //SPRAWDZ CORNER CASE'Y, MINIMALNE I MAKSYMALNE WEJŚCIE I WYJŚCIE //MODULO = 1 #include <cstdio> #include <algorithm> #define REP(i,n) for(int i=0;i<(n);++i) #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 foreach(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i) #define all(c) (c).begin(),(c).end() #define scanf(...) scanf(__VA_ARGS__)?:0 #define e1 first #define e2 second #define mp make_pair using namespace std; typedef long long ll; int k,sz[25],a[25];//={2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97}; int *num[25]; ll n,zak=1.1e8; int main() { scanf("%d%lld",&k,&n); REP(i,k) scanf("%d",&a[i]); if (n<=45e7) zak=n; ll x=1; while (x<=zak) sz[0]++,x*=a[0]; num[0]=new int[sz[0]]; num[0][0]=1; FOR(i,1,sz[0]-1) num[0][i]=a[0]*num[0][i-1]; FOR(i,1,k-1) { REP(j,i) REP(it,sz[j]) { ll x=num[j][it]*(ll)a[i]; while (x<=zak) sz[i]++,x*=a[i]; } num[i]=new int[sz[i]]; int poz=0; REP(j,i) REP(it,sz[j]) { ll x=(ll)num[j][it]*a[i]; while (x<=zak) num[i][poz++]=x,x*=a[i]; } } ll ans=0; REP(i,k) REP(j,sz[i]) if (num[i][j]>ans) ans=num[i][j]; if (zak==n) { printf("%lld\n",ans); return 0; } else { int size=0,poz=0; REP(i,k) size+=sz[i]; int tab[size]; REP(i,k) REP(j,sz[i]) tab[poz++]=num[i][j]; REP(i,k) delete[] num[i]; sort(tab,tab+size); FORD(i,size-1,0) { ll mv=n/tab[i]; if (mv>=tab[size-1]) { ans=max(ans,(ll)tab[i]*tab[size-1]); break; } else { int xd=*(upper_bound(tab,tab+size,mv)-1); ans=max(ans,(ll)tab[i]*xd); } } printf("%lld\n",ans); } }
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 | //PRZEMYSL ASSERTY //SPRAWDZ CORNER CASE'Y, MINIMALNE I MAKSYMALNE WEJŚCIE I WYJŚCIE //MODULO = 1 #include <cstdio> #include <algorithm> #define REP(i,n) for(int i=0;i<(n);++i) #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 foreach(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i) #define all(c) (c).begin(),(c).end() #define scanf(...) scanf(__VA_ARGS__)?:0 #define e1 first #define e2 second #define mp make_pair using namespace std; typedef long long ll; int k,sz[25],a[25];//={2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97}; int *num[25]; ll n,zak=1.1e8; int main() { scanf("%d%lld",&k,&n); REP(i,k) scanf("%d",&a[i]); if (n<=45e7) zak=n; ll x=1; while (x<=zak) sz[0]++,x*=a[0]; num[0]=new int[sz[0]]; num[0][0]=1; FOR(i,1,sz[0]-1) num[0][i]=a[0]*num[0][i-1]; FOR(i,1,k-1) { REP(j,i) REP(it,sz[j]) { ll x=num[j][it]*(ll)a[i]; while (x<=zak) sz[i]++,x*=a[i]; } num[i]=new int[sz[i]]; int poz=0; REP(j,i) REP(it,sz[j]) { ll x=(ll)num[j][it]*a[i]; while (x<=zak) num[i][poz++]=x,x*=a[i]; } } ll ans=0; REP(i,k) REP(j,sz[i]) if (num[i][j]>ans) ans=num[i][j]; if (zak==n) { printf("%lld\n",ans); return 0; } else { int size=0,poz=0; REP(i,k) size+=sz[i]; int tab[size]; REP(i,k) REP(j,sz[i]) tab[poz++]=num[i][j]; REP(i,k) delete[] num[i]; sort(tab,tab+size); FORD(i,size-1,0) { ll mv=n/tab[i]; if (mv>=tab[size-1]) { ans=max(ans,(ll)tab[i]*tab[size-1]); break; } else { int xd=*(upper_bound(tab,tab+size,mv)-1); ans=max(ans,(ll)tab[i]*xd); } } printf("%lld\n",ans); } } |