质数
C++ 代码
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
const int N = 1e6 + 10;
bool st[N];
int prime[N];
int k,idx = 1;
int judge()
{
memset(st,false,sizeof st);
for(int i = 2;i <= N; i++)
{
if(!st[i]) prime[idx++] = i;
for(int j = 1;prime[j]<=N/i;j++)
{
st[prime[j]*i] = true;
if(i%prime[j]==0) break;
}
}
}
int main()
{
judge();
while(cin>>k)
{
cout<<prime[k]<<endl;
}
return 0;
}