#include<bits/stdc++.h> using namespace std; bool isprime(int x) { int sqrtqz=sqrt(x); sqrtqz++; bool last=true; for (int i=2;i<sqrtqz;i++)//从7.5s~7.6s提升到0.58s~0.6s { if (x%i==0) { last=false; break;//从0.58s~0.6s提升到0.51s~0.56s } } return last; } int main() { for (int i=2;i<=100000;i++) { if (isprime(i)==true) { cout<<i<<" "; } } return 0; }