是的,有O(N)
主发电机在那里(其中N
是质量数,而不是在亚线性时间内运行的质量数的范围大小)。例如欧拉公式(从项目欧拉27):公式的输出
p = n² + n + 41; n={0,1,2,...39}
这里比较对素数:
Output: 41,43,47,53,...61,...71,......83,...97,................113,....131,............151,............173,................197,........223,....................251,....................281,................313,............347,........................383,....................421,........................461,........................503,................547,........................593,............................641,................................691,........................743,........................797,............................853,................................911,............................971,.........................................1033,.............................................1097,...................................1163,...................................1231,.......................................................1301,...................................1373,........................................1447,.......................................................1523,..................................................1601
Primes: 41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,193,197,199,211,223,227,229,233,239,241,251,257,263,269,271,277,281,283,293,307,311,313,317,331,337,347,349,353,359,367,373,379,383,389,397,401,409,419,421,431,433,439,443,449,457,461,463,467,479,487,491,499,503,509,521,523,541,547,557,563,569,571,577,587,593,599,601,607,613,617,619,631,641,643,647,653,659,661,673,677,683,691,701,709,719,727,733,739,743,751,757,761,769,773,787,797,809,811,821,823,827,829,839,853,857,859,863,877,881,883,887,907,911,919,929,937,941,947,953,967,971,977,983,991,997,1009,1013,1019,1021,1031,1033,1039,1049,1051,1061,1063,1069,1087,1091,1093,1097,1103,1109,1117,1123,1129,1151,1153,1163,1171,1181,1187,1193,1201,1213,1217,1223,1229,1231,1237,1249,1259,1277,1279,1283,1289,1291,1297,1301,1303,1307,1319,1321,1327,1361,1367,1373,1381,1399,1409,1423,1427,1429,1433,1439,1447,1451,1453,1459,1471,1481,1483,1487,1489,1493,1499,1511,1523,1531,1543,1549,1553,1559,1567,1571,1579,1583,1597,1601
正如你可以看到它产生为了素数,但不是所有的人。这种发生器限于特定的范围。还有数字方法可以在特定范围内生成此类公式,但要获得它们比O(N)
困难得多。
你需要的是做一个近似多项式,它可以在<1,100>
上工作,但是为了保持精度(或者明智地使用它),可能需要高次多项式。所以谷歌多项式拟合但更好的选择将是PSLQ。
有关如何提高筛黄金发生器看看更多的想法:
https://codegolf.stackexchange.com/questions/6309/list-of-first-n-prime-numbers-most-efficiently-and-in-shortest-code –
你的程序是O(n^1.5) ,而不是O(n^2)。查看需要O(n loglogn)的Eratosthenes筛,或者更快的Atkin筛。 – interjay
注意:评论是off-by-1'//将数字从1到100放置在数组中' - >'将数字从0到99放置在数组中' – chux