素数等差数列

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<vector>
#include<cstring>
using namespace std;
bool used[30001];
vector<int>num;
int main()
{
int i,j;
memset(used,false,sizeof(used));
for(i=2;i<=10000;i++)
{
if(used[i])continue;
if(!used[i])
{
num.push_back(i);
}
for(j=i*2;j<=10000;j+=i)
{
used[j]=true;
}
}
int ok=num.size();
int n;
while(scanf("%d",&n)!=EOF){
int len=0;
if(n<=1)
{
printf("No number sequence\n");continue;
}
for(i=0;i<ok;i++)
{
if(num[i]<=n)
{
len+=1;continue;
}
else
{
break;
}
}
bool flag=false;
int j;
int sum;
sum=0;
for(i=0;i<len-2;i++)
{
for(j=2;j<=num[len-1]/2+1;j++)
{
if(used[num[i]])
continue;
if(used[num[i]+j])continue;
if(used[num[i]+2*j])continue;
if(num[i]>num[len-1])break;
else if(num[i]+2*j>num[len-1])break;
else if(num[i]+j>num[len-1])break;
printf("%d %d %d\n",num[i],num[i]+j,num[i]+2*j);
flag=true;
// sum++;
}
}
//printf("%d\n",sum);
if(!flag)
printf("No number sequence\n");
}
return 0;
}