在埃拉托斯特尼筛法中，要筛选出不大于 n 的所有素数，最外层循环应该遍历什么范围（ ）？
vector<int> sieveOfEratosthenes(int n) {
std::vector<bool> isPrime(n + 1, true);
std::vector<int> primes;
_______________________ {
if (isPrime[i]) {
primes.push_back(i);
for (int j = i * i; j <= n; j += i) {
isPrime[j] = false;
}
}
}
for (int i = sqrt(n) + 1; i <= n; ++i) {
if (isPrime[i]) {
primes.push_back(i);
}
}
return primes;
}
- A. for (int i = 2; i <= n; ++i)
- B. for (int i = 1; i < n; ++i)
- C. for (int i = 2; i <= sqrt(n); ++i)
- D. for (int i = 1; i <= sqrt(n); ++i)
正确答案：C