UVA 10837(p345)----A Research Problem

来源：互联网发布：凯立德导航端口查询编辑：程序博客网时间：2024/05/22 03:49
#include<iostream>#include<cstdio>#include<cstring>using namespace std;const int maxp=10000+10;bool vis[maxp],done[222];int pri[maxp],pnum,cur_p[555],cnt_p[555];int tot,ans,v[maxp];void get_prime(int n){    vis[1]=1;    for(int i=2;i*i<=n;i++)        if(!vis[i])          for(int j=i*i;j<=n;j+=i)            vis[j]=1;    pnum=0;    for(int i=2;i<=n;i++)        if(!vis[i])          pri[pnum++]=i;}void split(int n){    tot=0;    for(int i=0;i<pnum&&(pri[i]-1)*(pri[i]-1)<=n;i++)        if(n%(pri[i]-1)==0)           cur_p[tot++]=pri[i];}int judge(int n){    if(n==1) return n;    n++;    for(int i=0;i<pnum&&pri[i]*pri[i]<=n;i++)        if(n%pri[i]==0) return -1;    for(int i=0;i<tot;i++)        if(v[i]&&n==cur_p[i]) return -1;    return n;}void dfs(int left,int now,int c){    if(c==tot)    {        int ret=judge(now);        if(ret>0)            ans=min(ans,left*ret);        return ;    }    dfs(left,now,c+1);    if(now%(cur_p[c]-1)==0)    {        v[c]=1;        left*=cur_p[c];        now/=cur_p[c]-1;        while(1)        {            dfs(left,now,c+1);            if(now%cur_p[c]) return ;            now/=cur_p[c];            left*=cur_p[c];        }        v[c]=0;    }}void solve(int n){    memset(done,false,sizeof(done));    memset(v,false,sizeof(v));    ans=1e8*2;    split(n);    dfs(1,n,0);}int main(){    get_prime(10000);    int n,cas=1;    while(scanf("%d",&n)!=EOF&&n)    {        solve(n);        printf("Case %d: %d %d\n",cas++,n,ans);    }    return 0;}
0 0