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最新推荐文章于 2025-08-10 08:58:43 发布

转载最新推荐文章于 2025-08-10 08:58:43 发布 · 49 阅读

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原文链接：http://www.cnblogs.com/asenyang/p/6770177.html

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#数据结构与算法

public class Solution {
    public int CountPrimes(int n) {
        if (n <= 2)
            {
                return 0;
            }

            long[] prime = new long[n + 1];
            bool[] mark = new bool[n + 1];

            int primeSize = 0;

            for (int i = 1; i < n; i++)
            {
                mark[i] = false;
            }

            for (long i = 2; i < n; i++)
            {
                if (mark[i] == true)
                {
                    continue;
                }
                prime[primeSize++] = i;
                for (long j = i * i; j <= n; j += i)
                {
                    mark[j] = true;
                }
            }

            return primeSize;
    }
}