// Copyright 2014 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. extern crate collections; use std::collections::Bitv; use std::num::Float; fn main() { // Generate sieve of Eratosthenes for n up to 1e6 let n = 1000000_usize; let mut sieve = Bitv::from_elem(n+1, true); let limit: uint = (n as f32).sqrt() as uint; for i in 2..limit+1 { if sieve[i] { let mut j = 0; while i*i + j*i <= n { sieve.set(i*i+j*i, false); j += 1; } } } for i in 2..n+1 { if sieve[i] { } } }