[HAOI2007]\u53cd\u7d20\u6570ant<\/p>\n
Time Limit:10000MS Memory Limit:165536K
Total Submit:54 Accepted:33
Case Time Limit:1000MS<\/p>\n
Description <\/strong><\/p>\n \u53cd\u8d28\u6570\uff08ant\uff09 Input <\/strong> <\/em><\/p>\n \u4e00\u4e2a\u6570N\uff081<=N<=2,000,000,000\uff09\u3002 <\/p>\n <\/em><\/p>\n Output <\/strong> <\/em><\/p>\n \u4e0d\u8d85\u8fc7N\u7684\u6700\u5927\u7684\u53cd\u8d28\u6570\u3002 <\/p>\n <\/em><\/p>\n Sample Input <\/strong> <\/em><\/p>\n 1000<\/em><\/p>\n Sample Output <\/strong> <\/em><\/p>\n 840<\/em><\/p>\n Source #include<cstdio> [HAOI2007]\u53cd\u7d20\u6570ant Time Limit:10000MS Memory Limit:165536KTotal Submit:54 Accepted:33 Case Time Limit:1000MS Description \u53cd\u8d28\u6570\uff08ant\uff09 \u5bf9\u4e8e\u4efb\u4f55\u6b63\u6574\u6570x\uff0c\u5176\u7ea6\u6570\u7684\u4e2a\u6570\u8bb0\u4f5cg(x)\u3002\u4f8b\u5982g(1)=1\u3001g(6)=4\u3002 \u5982\u679c\u67d0\u4e2a\u6b63\u6574\u6570x\u6ee1\u8db3\uff1ag(x)>g(i) 0 Input \u4e00\u4e2a\u6570N\uff081<=N<=2,000,000,000\uff09\u3002 Output \u4e0d\u8d85\u8fc7N\u7684\u6700\u5927\u7684\u53cd\u8d28\u6570\u3002 Sample Input 1000 Sample Output 840 Source\u53ea\u80fd\u641c\u5457\u3002\u3002\u9996\u5148\u7d20\u56e0\u5b50\u6700\u591a\u662f\u524d10\u4e2a\uff0c\u540c\u65f6\u5404\u4e2a\u56e0\u5b50\u7684\u5e42\u80af\u5b9a\u9012\u51cf\u3002\u3002\u7136\u540e\u5c31\u968f\u4fbf\u641c\u4e86\u3002\u3002\u5b9e\u9645\u4e0a\u8fd8\u53ef\u4ee5\u52a0\u4e00\u4e9b\u526a\u679d\u7684\uff0c\u6bd4\u5982\u4f30\u4ef7\u51fd\u6570\u4e4b\u7c7b\u7684\uff0c\u8bbe\u5f53\u524d\u641c\u5230\u7d20\u6570p\uff0c\u4e0a\u9650\u4e3aN\uff0c\u90a3\u4e48\u663e\u7136\u6700\u591a\u8fd8\u80fd\u5c06\u7d20\u56e0\u5b50*2^Log\uff08p,N\uff09\u500d\u3002\u3002Code\uff1a #include<cstdio>#include<iostream>#include<algorithm>#include<string>#include<vector>#include<cstring>#define rep(i,n) for(int i=0;i<n;i++)#define pb push_backusing namespace std;const int inf=~0U>>1,maxp=1000;int Ps[maxp],pnt=0,N;typedef long long ll;bool IsPrime(int p){ if(p==2)return true; if(p%2==0) return false; for(int i=3;i*i<=p;i+=2)if(p%i==0) return false; return true;}struct Answer{ int […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[10],"tags":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=\/wp\/v2\/posts\/203"}],"collection":[{"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=203"}],"version-history":[{"count":0,"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=\/wp\/v2\/posts\/203\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=203"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=203"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=203"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\u5bf9\u4e8e\u4efb\u4f55\u6b63\u6574\u6570x\uff0c\u5176\u7ea6\u6570\u7684\u4e2a\u6570\u8bb0\u4f5cg(x)\u3002\u4f8b\u5982g(1)=1\u3001g(6)=4\u3002
\u5982\u679c\u67d0\u4e2a\u6b63\u6574\u6570x\u6ee1\u8db3\uff1ag(x)>g(i) 0<\/p>\n
\u53ea\u80fd\u641c\u5457\u3002\u3002\u9996\u5148\u7d20\u56e0\u5b50\u6700\u591a\u662f\u524d10\u4e2a\uff0c\u540c\u65f6\u5404\u4e2a\u56e0\u5b50\u7684\u5e42\u80af\u5b9a\u9012\u51cf\u3002\u3002\u7136\u540e\u5c31\u968f\u4fbf\u641c\u4e86\u3002\u3002\u5b9e\u9645\u4e0a\u8fd8\u53ef\u4ee5\u52a0\u4e00\u4e9b\u526a\u679d\u7684\uff0c\u6bd4\u5982\u4f30\u4ef7\u51fd\u6570\u4e4b\u7c7b\u7684\uff0c\u8bbe\u5f53\u524d\u641c\u5230\u7d20\u6570p\uff0c\u4e0a\u9650\u4e3aN\uff0c\u90a3\u4e48\u663e\u7136\u6700\u591a\u8fd8\u80fd\u5c06\u7d20\u56e0\u5b50*2^Log\uff08p,N\uff09\u500d\u3002\u3002
Code\uff1a
<\/strong><\/em><\/p>\n
#include<iostream>
#include<algorithm>
#include<string>
#include<vector>
#include<cstring>
#define rep(i,n) for(int i=0;i<n;i++)
#define pb push_back
using namespace std;
const int inf=~0U>>1,maxp=1000;
int Ps[maxp],pnt=0,N;
typedef long long ll;
bool IsPrime(int p)
{
if(p==2)return true;
if(p%2==0) return false;
for(int i=3;i*i<=p;i+=2)if(p%i==0) return false;
return true;
}
struct Answer
{
int ans,num;
Answer(){ans=1;num=1;}
void Update(const Answer&a)
{
if(a.ans>ans||(a.ans==ans&&a.num<num)) *this=a;
}
Answer Mul(int x,int c)
{
Answer ret;
ret.ans=ans*(c+1);
ret.num=num*x;
return ret;
}
}Ans;
void GetPrime()
{
for(int i=2;i<maxp&&pnt<9;i++) if(IsPrime(i)) Ps[pnt++]=i;
}
void dfs(int now,int pre,ll N,Answer a)
{
if(N<Ps[now]||now>=pnt||!pre){Ans.Update(a);return;}
ll s=1;rep(i,pre) s*=Ps[now];
for(int i=pre;i>=0;–i)
{
if(s<=N)dfs(now+1,i,N\/s,a.Mul(s,i));
s\/=Ps[now];
}
}
int main()
{
\/\/freopen("in","r",stdin);
\/\/freopen("out","w",stdout);
cin>>N;
GetPrime();
dfs(0,15,N,Answer());
long long k=1;
cout<<Ans.num<<endl;
}<\/p>\n","protected":false},"excerpt":{"rendered":"