#include<bits/stdc++.h> #define ALL(X) X.begin(),X.end() #define FOR(I,A,B) for(int (I) = (A); (I) <= (B); (I)++) #define FORW(I,A,B) for(int (I) = (A); (I) < (B); (I)++) #define FORD(I,A,B) for(int (I) = (A); (I) >= (B); (I)--) #define CLEAR(X) memset(X,0,sizeof(X)) #define SIZE(X) int(X.size()) #define CONTAINS(A,X) (A.find(X) != A.end()) #define PB push_back #define MP make_pair #define X first #define Y second using namespace std; template<typename T, typename U> ostream& operator << (ostream& os, const pair<T, U> &_p) { return os << "(" << _p.X << "," << _p.Y << ")"; } template<typename T> ostream& operator << (ostream &os, const vector<T>& _V) { bool f = true; os << "["; for(auto v: _V) { os << (f ? "" : ",") << v; f = false; } return os << "]"; } template<typename T> ostream& operator << (ostream &os, const set<T>& _S) { bool f = true; os << "("; for(auto s: _S) { os << (f ? "" : ",") << s; f = false; } return os << ")"; } template<typename T, typename U> ostream& operator << (ostream &os, const map<T, U>& _M) { return os << set<pair<T, U>>(ALL(_M)); } typedef unsigned long long slong; typedef long double ldouble; typedef pair<int,int> pii; const slong INF = 1000000100; const ldouble EPS = 1e-9; template<class TH> void _dbg(const char *sdbg, TH h){cerr<<sdbg<<"="<<h<<"\n";} template<class TH, class... TA> void _dbg(const char *sdbg, TH h, TA... a) { while(*sdbg!=',')cerr<<*sdbg++;cerr<<"="<<h<<","; _dbg(sdbg+1, a...); } #ifdef LOCALs #define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__) #else #define debug(...) (__VA_ARGS__) #define cerr if(0)cout #endif vector<slong> small, mid, big; vector<slong> v, vmid, vbig; slong N; slong ans = 1; inline int grt(slong a, slong b, slong c) { /// a * b > c ? if((64 - __builtin_clzll(a)) + (64 - __builtin_clzll(b)) > (65 - __builtin_clzll(c))) return 1; //if(double(a) * double(b) > 2.0 * double(c)) return 1; return (a * b > c); } const int MAXM = 100042; int low[MAXM+42]; slong sum = 0, itcnt = 0, sums = 0; void gen(vector<slong> &p, vector<slong> &vs, slong cur, int i, int s) { if(i >= SIZE(p)) return; slong tmp = 1; gen(p, vs, cur, i+1, s); while(42) { if(grt(cur * tmp, p[i], N)) break; tmp *= p[i]; /// cur * tmp to osiagalna liczba slong x = cur * tmp; if(s) { if(x > 1) vs.PB(x); if(x <= N) ans = max(ans, x); } if(s != 1 && x <= N) { /// big or mid ans = max(ans, x); for(slong z : vmid) { if(grt(x, z, N)) break; slong xx = x * z; slong tg = 1; //tg = N / xx; /// wolno dziala :( int MAGIC = 3; if((xx << MAGIC) > N) { while(xx * (tg + 1) <= N) tg++; //sums++; } else tg = N / xx; slong y = xx; if(tg < MAXM) { y *= low[tg]; } else { //sum++; int st = 0, en = SIZE(v); while(st + 1 < en) { /// xx * v[st] <= N int shot = (st + en) / 2; if(v[shot] > tg) en = shot; else st = shot; //itcnt++; } y *= v[st]; } ans = max(ans, y); } } gen(p, vs, cur*tmp, i+1, s); } } void solve() { const int A = 11, B = 42; slong k, n; cin >> k >> n; N = n; FOR(i,1,k) { int x; cin >> x; if(x <= A) small.PB(x); else if(x <= B) mid.PB(x); else big.PB(x); } v.reserve(300000); v.PB(1); vmid.reserve(200000); vmid.PB(1); vbig.PB(1); gen(small, v, 1, 0, 1); sort(ALL(v)); for(slong x : v) { if(x < MAXM) low[x] = x; } FORW(i,1,MAXM) { if(!low[i]) low[i] = low[i-1]; } gen(mid, vmid, 1, 0, 2); sort(ALL(vmid)); gen(big, vbig, 1, 0, 0); //debug(SIZE(v), SIZE(vmid), SIZE(vbig)); cout << ans << "\n"; //debug(sums, sum,itcnt,itcnt/max(slong(1),sum)); //cin >> ans[0]; } int main() { ios_base::sync_with_stdio(0); solve(); }
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 | #include<bits/stdc++.h> #define ALL(X) X.begin(),X.end() #define FOR(I,A,B) for(int (I) = (A); (I) <= (B); (I)++) #define FORW(I,A,B) for(int (I) = (A); (I) < (B); (I)++) #define FORD(I,A,B) for(int (I) = (A); (I) >= (B); (I)--) #define CLEAR(X) memset(X,0,sizeof(X)) #define SIZE(X) int(X.size()) #define CONTAINS(A,X) (A.find(X) != A.end()) #define PB push_back #define MP make_pair #define X first #define Y second using namespace std; template<typename T, typename U> ostream& operator << (ostream& os, const pair<T, U> &_p) { return os << "(" << _p.X << "," << _p.Y << ")"; } template<typename T> ostream& operator << (ostream &os, const vector<T>& _V) { bool f = true; os << "["; for(auto v: _V) { os << (f ? "" : ",") << v; f = false; } return os << "]"; } template<typename T> ostream& operator << (ostream &os, const set<T>& _S) { bool f = true; os << "("; for(auto s: _S) { os << (f ? "" : ",") << s; f = false; } return os << ")"; } template<typename T, typename U> ostream& operator << (ostream &os, const map<T, U>& _M) { return os << set<pair<T, U>>(ALL(_M)); } typedef unsigned long long slong; typedef long double ldouble; typedef pair<int,int> pii; const slong INF = 1000000100; const ldouble EPS = 1e-9; template<class TH> void _dbg(const char *sdbg, TH h){cerr<<sdbg<<"="<<h<<"\n";} template<class TH, class... TA> void _dbg(const char *sdbg, TH h, TA... a) { while(*sdbg!=',')cerr<<*sdbg++;cerr<<"="<<h<<","; _dbg(sdbg+1, a...); } #ifdef LOCALs #define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__) #else #define debug(...) (__VA_ARGS__) #define cerr if(0)cout #endif vector<slong> small, mid, big; vector<slong> v, vmid, vbig; slong N; slong ans = 1; inline int grt(slong a, slong b, slong c) { /// a * b > c ? if((64 - __builtin_clzll(a)) + (64 - __builtin_clzll(b)) > (65 - __builtin_clzll(c))) return 1; //if(double(a) * double(b) > 2.0 * double(c)) return 1; return (a * b > c); } const int MAXM = 100042; int low[MAXM+42]; slong sum = 0, itcnt = 0, sums = 0; void gen(vector<slong> &p, vector<slong> &vs, slong cur, int i, int s) { if(i >= SIZE(p)) return; slong tmp = 1; gen(p, vs, cur, i+1, s); while(42) { if(grt(cur * tmp, p[i], N)) break; tmp *= p[i]; /// cur * tmp to osiagalna liczba slong x = cur * tmp; if(s) { if(x > 1) vs.PB(x); if(x <= N) ans = max(ans, x); } if(s != 1 && x <= N) { /// big or mid ans = max(ans, x); for(slong z : vmid) { if(grt(x, z, N)) break; slong xx = x * z; slong tg = 1; //tg = N / xx; /// wolno dziala :( int MAGIC = 3; if((xx << MAGIC) > N) { while(xx * (tg + 1) <= N) tg++; //sums++; } else tg = N / xx; slong y = xx; if(tg < MAXM) { y *= low[tg]; } else { //sum++; int st = 0, en = SIZE(v); while(st + 1 < en) { /// xx * v[st] <= N int shot = (st + en) / 2; if(v[shot] > tg) en = shot; else st = shot; //itcnt++; } y *= v[st]; } ans = max(ans, y); } } gen(p, vs, cur*tmp, i+1, s); } } void solve() { const int A = 11, B = 42; slong k, n; cin >> k >> n; N = n; FOR(i,1,k) { int x; cin >> x; if(x <= A) small.PB(x); else if(x <= B) mid.PB(x); else big.PB(x); } v.reserve(300000); v.PB(1); vmid.reserve(200000); vmid.PB(1); vbig.PB(1); gen(small, v, 1, 0, 1); sort(ALL(v)); for(slong x : v) { if(x < MAXM) low[x] = x; } FORW(i,1,MAXM) { if(!low[i]) low[i] = low[i-1]; } gen(mid, vmid, 1, 0, 2); sort(ALL(vmid)); gen(big, vbig, 1, 0, 0); //debug(SIZE(v), SIZE(vmid), SIZE(vbig)); cout << ans << "\n"; //debug(sums, sum,itcnt,itcnt/max(slong(1),sum)); //cin >> ans[0]; } int main() { ios_base::sync_with_stdio(0); solve(); } |