UVA 12542 Prime Substring 解题报告

//Time:16ms
//Memory:0KB
//Length:734B
#include <iostream>
#include <cstdio>
using namespace std;
#define MAXN 300
#define MAXM 100010
char str[MAXN];
bool vi[MAXM]={0};
int main()
{
//freopen("/home/moor/Code/input","r",stdin);
vi[1]=0;
for(int i=2;i<MAXM;++i)
if(!vi[i])
for(int j=i+i;j<MAXM;j+=i)
vi[j]=1;
while(scanf("%s",str))
{
int ans=0;
if(str[0]=='0'&&str[1]=='\0')   break;
for(int i=0;str[i];++i)
{
int tmp=0;
for(int j=i;str[j];++j)
{
tmp=tmp*10+str[j]-'0';
if(tmp>=MAXM)   break;
if(!vi[tmp])    ans=max(tmp,ans);
}
}
printf("%d\n",ans);
}
return 0;
}