#include<bits/stdc++.h> #define rep(i,a,b) for(int i=a;i<b;i++) #define per(i,a,b) for(int i=a;i>b;i--) #define repLL(i,a,b) for(LL i=(LL)a;i<(LL)b;i++) #define perLL(i,a,b) for(LL i=(LL)a;i>(LL)b;i--) #define debug5(a,b,c,d,e) cerr<<#a<<": "<<a<<" "<<#b<<": "<<b<<" "<<#c<<": "<<c<<" "<<#d<<": "<<d<<" "<<#e<<": "<<e<<endl; #define debug4(a,b,c,d) cerr<<#a<<": "<<a<<" "<<#b<<": "<<b<<" "<<#c<<": "<<c<<" "<<#d<<": "<<d<<endl; #define debug3(a,b,c) cerr<<#a<<": "<<a<<" "<<#b<<": "<<b<<" "<<#c<<": "<<c<<endl; #define debug2(a,b) cerr<<#a<<": "<<a<<" "<<#b<<": "<<b<<endl; #define debug(a) cerr<<#a<<": "<<a<<endl; #define pb push_back #define mp make_pair #define SZ(x) ((int)(x).size()) #define ALL(x) x.begin(),x.end() #define fi first #define se second #define _upgrade ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); using namespace std; typedef long long LL; typedef pair<int,int> PII; typedef pair<LL,LL> PLL; typedef vector<PII> VPII; typedef vector<PLL> VPLL; typedef vector<LL> VLL; typedef vector<int> VI; typedef vector<string> VS; typedef vector<char> VC; typedef long double LD; typedef pair<LD,LD> PLD; typedef vector<LD> VLD; typedef vector<PLD> VPLD; const int maxn=(1e6)+7; const int inf=(1e9)+7; const LL LLinf=(1e18)+7; const LD eps=1e-9; const LL mod=1e9+7; // ***************************** CODE ***************************** // bitset<maxn> zb; int odl[maxn]; VI P; int tab[(int)1e5]; int numer; inline bool czy(LL x) { for(auto s:P) while(x%s==0) x/=s; if(x==1LL) return 1LL; return 0LL; } LL rek(LL n,int kto) { if(n<maxn) return n-odl[n]; LL res=1LL; for(auto s:P) if(s>=kto) res=max(res,rek(n/s,s)*s); return res; } int main() { _upgrade int k; LL n; cin>>k>>n; rep(i,0,k) { int a; cin>>a; P.pb(a); } for(LL i=n;i>n-maxn;i--) if(czy(i)) { cout<<i<<endl; return 0; } n-=maxn-1; LL res=1LL; int dlu=0; rep(i,1,maxn) { bool a=czy(i); zb[i]=a; if(a==0) dlu++; else dlu=0; odl[i]=dlu; if(zb[i]) tab[numer++]=i; } if(n<10000000000LL) { rep(i,0,numer) { LL curr=n/(LL)tab[i]; if(curr<maxn) { curr-=odl[curr]; curr*=tab[i]; res=max(res,curr); } } cout<<res<<endl; return 0; } res=max(res,rek(n,0LL)); cout<<res<<endl; 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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 | #include<bits/stdc++.h> #define rep(i,a,b) for(int i=a;i<b;i++) #define per(i,a,b) for(int i=a;i>b;i--) #define repLL(i,a,b) for(LL i=(LL)a;i<(LL)b;i++) #define perLL(i,a,b) for(LL i=(LL)a;i>(LL)b;i--) #define debug5(a,b,c,d,e) cerr<<#a<<": "<<a<<" "<<#b<<": "<<b<<" "<<#c<<": "<<c<<" "<<#d<<": "<<d<<" "<<#e<<": "<<e<<endl; #define debug4(a,b,c,d) cerr<<#a<<": "<<a<<" "<<#b<<": "<<b<<" "<<#c<<": "<<c<<" "<<#d<<": "<<d<<endl; #define debug3(a,b,c) cerr<<#a<<": "<<a<<" "<<#b<<": "<<b<<" "<<#c<<": "<<c<<endl; #define debug2(a,b) cerr<<#a<<": "<<a<<" "<<#b<<": "<<b<<endl; #define debug(a) cerr<<#a<<": "<<a<<endl; #define pb push_back #define mp make_pair #define SZ(x) ((int)(x).size()) #define ALL(x) x.begin(),x.end() #define fi first #define se second #define _upgrade ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); using namespace std; typedef long long LL; typedef pair<int,int> PII; typedef pair<LL,LL> PLL; typedef vector<PII> VPII; typedef vector<PLL> VPLL; typedef vector<LL> VLL; typedef vector<int> VI; typedef vector<string> VS; typedef vector<char> VC; typedef long double LD; typedef pair<LD,LD> PLD; typedef vector<LD> VLD; typedef vector<PLD> VPLD; const int maxn=(1e6)+7; const int inf=(1e9)+7; const LL LLinf=(1e18)+7; const LD eps=1e-9; const LL mod=1e9+7; // ***************************** CODE ***************************** // bitset<maxn> zb; int odl[maxn]; VI P; int tab[(int)1e5]; int numer; inline bool czy(LL x) { for(auto s:P) while(x%s==0) x/=s; if(x==1LL) return 1LL; return 0LL; } LL rek(LL n,int kto) { if(n<maxn) return n-odl[n]; LL res=1LL; for(auto s:P) if(s>=kto) res=max(res,rek(n/s,s)*s); return res; } int main() { _upgrade int k; LL n; cin>>k>>n; rep(i,0,k) { int a; cin>>a; P.pb(a); } for(LL i=n;i>n-maxn;i--) if(czy(i)) { cout<<i<<endl; return 0; } n-=maxn-1; LL res=1LL; int dlu=0; rep(i,1,maxn) { bool a=czy(i); zb[i]=a; if(a==0) dlu++; else dlu=0; odl[i]=dlu; if(zb[i]) tab[numer++]=i; } if(n<10000000000LL) { rep(i,0,numer) { LL curr=n/(LL)tab[i]; if(curr<maxn) { curr-=odl[curr]; curr*=tab[i]; res=max(res,curr); } } cout<<res<<endl; return 0; } res=max(res,rek(n,0LL)); cout<<res<<endl; return 0; } |