Editorial for Số nguyên tố!
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Submitting an official solution before solving the problem yourself is a bannable offence.
Submitting an official solution before solving the problem yourself is a bannable offence.
Lưu ý: Các code mẫu dưới đây chỉ mang tính tham khảo và có thể không AC được bài tập này
Code mẫu của happyboy99x
#include<cstring> #include<iostream> using namespace std; typedef unsigned long long Long; const int MAX = 3e6; bool isPrime[MAX + 1]; int p[MAX], nPrime; void eratos() { memset(isPrime, -1, sizeof isPrime); isPrime[0] = isPrime[1] = 0; for(int i = 2; i * i <= MAX; ++i) if(isPrime[i]) for(int j = i + i; j <= MAX; j += i) isPrime[j] = 0; for(int i = 0; i <= MAX; ++i) if(isPrime[i]) p[nPrime++] = i; } bool solutionExists(Long n, int k) { Long product = 1; for(int i = 0; i < k; ++i) product *= p[i]; return product <= n; } void solve(Long n, int k) { if(!solutionExists(n, k)) cout << "-1\n"; else { int l = 0, h = nPrime - k; while(l < h) { int m = (l + h + 1) / 2; bool ok = true; Long product = 1; for(int i = m; i < m + k; ++i) if(n / product >= (Long) p[i]) product *= p[i]; else ok = false; if(ok) l = m; else h = m-1; } Long res = 1; for(int i = l; i < l + k; ++i) res *= p[i]; cout << res << "\n"; } } int main() { eratos(); int tc; cin >> tc; Long n; int k; while(tc--) cin >> n >> k, solve(n, k); return 0; }
Code mẫu của ladpro98
program c11pnum; uses math; const maxP=2642246; fi=''; var a:array[1..maxP] of qword; sieve:array[1..maxP] of boolean; n:qword; d,k,t,tt:longint; inp:text; procedure init; var i,j:longint; begin for i:=2 to trunc(sqrt(maxP)) do begin if not sieve[i] then begin j:=i*i; while j<=maxP do begin sieve[j]:=true; inc(j,i); end; end; end; for i:=2 to maxP do if not sieve[i] then begin inc(d); a[d]:=i; end; end; function check(i:longint):boolean; var s,t:qword; j:longint; begin s:=1; for j:=i to i+k-1 do begin t:=n div a[j]; if s<=t then s:=s*a[j] else exit(false); end; exit(true); end; function cal(i:longint):qword; var s:qword; j:longint; begin s:=1; for j:=i to i+k-1 do s:=s*a[j]; exit(s); end; procedure process; var s:qword; i,l,r,m:longint; begin s:=1; for i:=1 to k do s:=s*a[i]; if s>n then begin writeln(-1); exit; end; l:=1;r:=d-k+1; while l<=r do begin m:=(l+r) shr 1; if check(m) then begin s:=cal(m); l:=m+1; end else r:=m-1; end; writeln(s); end; begin assign(inp,fi); reset(inp); readln(inp,t); init; for tt:=1 to t do begin read(inp,n); read(inp,k); process; end; close(inp); end.
Code mẫu của RR
#include <sstream> #include <iomanip> #include <iostream> #include <cstdio> #include <cstring> #include <cstdlib> #include <cmath> #include <algorithm> #include <vector> #include <set> #include <map> #include <stack> #include <queue> #include <string> #include <deque> #include <complex> #define FOR(i,a,b) for(int i=(a),_b=(b); i<=_b; i++) #define FORD(i,a,b) for(int i=(a),_b=(b); i>=_b; i--) #define REP(i,a) for(int i=0,_a=(a); i<_a; i++) #define FORN(i,a,b) for(int i=(a),_b=(b);i<_b;i++) #define DOWN(i,a,b) for(int i=a,_b=(b);i>=_b;i--) #define SET(a,v) memset(a,v,sizeof(a)) #define sqr(x) ((x)*(x)) #define ll long long #define F first #define S second #define PB push_back #define MP make_pair #define DEBUG(x) cout << #x << " = "; cout << x << endl; #define PR(a,n) cout << #a << " = "; FOR(_,1,n) cout << a[_] << ' '; cout << endl; #define PR0(a,n) cout << #a << " = "; REP(_,n) cout << a[_] << ' '; cout << endl; using namespace std; int sieve[3000111]; int nprime; long long primes[3000111]; unsigned long long n; int k; void init() { FOR(i,2,1800) if (!sieve[i]) { int j = i*i; while (j <= 3000000) { sieve[j] = 1; j += i; } } FOR(i,2,3000000) if (!sieve[i]) { ++nprime; primes[nprime] = i; } } void solve() { unsigned long long res = 0; FOR(i,1,nprime-k+1) { unsigned long long prod = 1LL; bool overflow = false; FOR(j,i,i+k-1) { if (prod > n/primes[j]) { overflow = true; break; } prod = prod * primes[j]; } if (!overflow && prod <= n) { if (prod > res) res = prod; } } if (!res) cout << -1 << endl; else cout << res << endl; } int main() { init(); int ntest; cin >> ntest; while (ntest--) { cin >> n >> k; solve(); } return 0; }
Code mẫu của hieult
#include <set> #include <map> #include <list> #include <cmath> #include <queue> #include <stack> #include <cstdio> #include <string> #include <vector> #include <cstdlib> #include <cstring> #include <sstream> #include <iomanip> #include <iostream> #include <algorithm> #include <ctime> #include <deque> #include <bitset> #include <cctype> #include <utility> using namespace std; typedef long long ll; typedef long double ld; typedef unsigned int ui; typedef unsigned long long ull; #define Rep(i,n) for(int i = 0; i < (n); ++i) #define Repd(i,n) for(int i = (n)-1; i >= 0; --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 Fit(i,v) for(__typeof((v).begin()) i = (v).begin(); i != (v).end(); ++i) #define Fitd(i,v) for(__typeof((v).rbegin()) i = (v).rbegin(); i != (v).rend(); ++i) #define mp make_pair #define pb push_back #define fi first #define se second #define sz(a) ((int)(a).size()) #define all(a) (a).begin(), (a).end() #define ms(a,x) memset(a, x, sizeof(a)) template<class F, class T> T convert(F a, int p = -1) { stringstream ss; if (p >= 0) ss << fixed << setprecision(p); ss << a; T r; ss >> r; return r; } template<class T> T gcd(T a, T b) { T r; while (b != 0) { r = a % b; a = b; b = r; } return a; } template<class T> T lcm(T a, T b) { return a / gcd(a, b) * b; } template<class T> T sqr(T x) { return x * x; } template<class T> T cube(T x) { return x * x * x; } template<class T> int getbit(T s, int i) { return (s >> i) & 1; } template<class T> T onbit(T s, int i) { return s | (T(1) << i); } template<class T> T offbit(T s, int i) { return s & (~(T(1) << i)); } template<class T> int cntbit(T s) { return s == 0 ? 0 : cntbit(s >> 1) + (s & 1); } const int bfsz = 1 << 16; char bf[bfsz + 5]; int rsz = 0; int ptr = 0; char gc() { if (rsz <= 0) { ptr = 0; rsz = (int) fread(bf, 1, bfsz, stdin); if (rsz <= 0) return EOF; } --rsz; return bf[ptr++]; } void ga(char &c) { c = EOF; while (!isalpha(c)) c = gc(); } int gs(char s[]) { int l = 0; char c = gc(); while (isspace(c)) c = gc(); while (c != EOF && !isspace(c)) { s[l++] = c; c = gc(); } s[l] = '\0'; return l; } template<class T> bool gi(T &v) { v = 0; char c = gc(); while (c != EOF && c != '-' && !isdigit(c)) c = gc(); if (c == EOF) return false; bool neg = c == '-'; if (neg) c = gc(); while (isdigit(c)) { v = v * 10 + c - '0'; c = gc(); } if (neg) v = -v; return true; } typedef pair<int, int> II; const ld PI = acos(-1.0); const ld eps = 1e-9; const int dr[] = { 0, 0, -1, +1 , -1, -1, +1, +1}; const int dc[] = { -1, +1, 0, 0 , -1, +1, -1, +1}; const int inf = (int) 1e9 + 5; const ll linf = (ll) 1e16 + 5; const ll mod = (ll) 1e9 + 7; const int maxn = 100 + 5; #define ok puts("ok") #define maxn 6000005 int test, k, size; unsigned long long n, prime[maxn]; template<int MAXP> struct BitSieve { #define isOn(x) ( p[x >> 6] & ( 1 << ( (x & 63) >> 1) ) ) #define turnOn(x) ( p[x >> 6] |= ( 1 << ( (x & 63) >> 1 ) ) ) int p[(MAXP >> 6) + 1]; BitSieve() { for (int i = 3; i * i <= MAXP; i += 2) { if (!isOn(i)) { int ii = i * i, i2 = i << 1; for (int j = ii; j <= MAXP; j += i2) turnOn(j); } } } bool operator [] (const int x) { return x > 1 && (x == 2 || ( (x & 1) && !isOn(x) ) ); } }; BitSieve<10000000> B; void init(){ size = 0; For(i, 2, 10000000 - 2) if(B[i]){ prime[size++] = i; } } int main() { // freopen("in.txt", "r", stdin); init(); cin >> test; Rep(run, test){ cin >> n >> k; unsigned long long res = 1; Rep(i, k - 1) res *= prime[i]; if(res * prime[k - 1] > n){ cout << -1 << endl; continue; } for(int i = k - 1; i < size; i++){ res = res * prime[i] / prime[i - k + 1]; if(res > n / prime[i + 1]){ cout << res * prime[i - k + 1] << endl; break; } } } return 0; }
Code mẫu của skyvn97
#include<stdio.h> #include<vector> using namespace std; typedef unsigned long long ull; ull MAX; const ull MAXV=3*10e5; vector <ull> pl; int t,c; ull n; int k; bool pr[MAXV]; void eratosthene(void) { int i,j; for (i=2;i<MAXV;i=i+1) { if (!pr[i]) { pl.push_back(i); for (j=2*i;j<MAXV;j=j+i) pr[j]=true; } } } void process(void) { ull p1,p2; int i; scanf("%llu",&n); scanf("%d",&k); p1=1; for (i=1;i<=k;i=i+1) p1=p1*pl[i-1]; if (p1>n) { printf("-1\n"); return; } for (i=k+1;i<=pl.size();i=i+1) { p2=p1; p2=(p2/pl[i-k-1])*pl[i-1]; if (p2<p1) { printf("%llu\n",p1); return; } if (p2>n) { printf("%llu\n",p1); return; } p1=p2; } } int main(void) { eratosthene(); scanf("%d",&t); for (c=1;c<=t;c=c+1) process(); }
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