“埃氏篩法”是一種高效的求N以內素數的演算法，時間複雜度為O（nloglogn）,求1000以內素數的“埃氏篩法”程式碼實現如下：

#include<cstdio>
#include<cmath>

int num[1001] = {0};
int primeCount = 0;
int prime[1001];

void findPrime() {
	
	for (int i = 2; i <= 1000; ++i) {
		if (!num[i]) {
			primeCount++;
			prime[primeCount] = i;
			for (int j = 2 * i; j <= 1000; j += i) { 
				num[j] = 1;
				
			}
		}
  }
}

int main() {
	findPrime();
	for (int i = 1; i < primeCount; ++i) {
		if (i&&i % 10 == 0) printf("%3d\n", prime[i]);
		else printf("%3d ", prime[i]);
	}
	
}