PrimeFinder.java
2.49 KB
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/**
*
*/
package is2.data;
import java.util.Arrays;
/**
* @author Dr. Bernd Bohnet, 13.05.2010
*
*
*/
public class PrimeFinder {
public PrimeFinder() {
}
public static final int nextPrime(int desiredCapacity) {
int i = Arrays.binarySearch(primeCapacities, desiredCapacity);
if (i < 0)
i = -i - 1;
return primeCapacities[i];
}
public static final int largestPrime = 2147483647;
private static final int primeCapacities[] = { 2147483647, 5, 11, 23, 47, 97, 197, 397, 797, 1597, 3203, 6421,
12853, 25717, 51437, 102877, 205759, 411527, 823117, 1646237, 3292489, 6584983, 13169977, 26339969,
52679969, 105359939, 210719881, 421439783, 842879579, 1685759167, 433, 877, 1759, 3527, 7057, 14143, 28289,
56591, 113189, 226379, 452759, 905551, 1811107, 3622219, 7244441, 14488931, 28977863, 57955739, 115911563,
231823147, 463646329, 927292699, 1854585413, 953, 1907, 3821, 7643, 15287, 30577, 61169, 122347, 244703,
489407, 978821, 1957651, 3915341, 7830701, 15661423, 31322867, 62645741, 125291483, 250582987, 501165979,
1002331963, 2004663929, 1039, 2081, 4177, 8363, 16729, 33461, 66923, 133853, 267713, 535481, 1070981,
2141977, 4283963, 8567929, 17135863, 34271747, 68543509, 137087021, 274174111, 548348231, 1096696463, 31,
67, 137, 277, 557, 1117, 2237, 4481, 8963, 17929, 35863, 71741, 143483, 286973, 573953, 1147921, 2295859,
4591721, 9183457, 18366923, 36733847, 73467739, 146935499, 293871013, 587742049, 1175484103, 599, 1201,
2411, 4831, 9677, 19373, 38747, 77509, 155027, 310081, 620171, 1240361, 2480729, 4961459, 9922933, 19845871,
39691759, 79383533, 158767069, 317534141, 635068283, 1270136683, 311, 631, 1277, 2557, 5119, 10243, 20507,
41017, 82037, 164089, 328213, 656429, 1312867, 2625761, 5251529, 10503061, 21006137, 42012281, 84024581,
168049163, 336098327, 672196673, 1344393353, 3, 7, 17, 37, 79, 163, 331, 673, 1361, 2729, 5471, 10949,
21911, 43853, 87719, 175447, 350899, 701819, 1403641, 2807303, 5614657, 11229331, 22458671, 44917381,
89834777, 179669557, 359339171, 718678369, 1437356741, 43, 89, 179, 359, 719, 1439, 2879, 5779, 11579,
23159, 46327, 92657, 185323, 370661, 741337, 1482707, 2965421, 5930887, 11861791, 23723597, 47447201,
94894427, 189788857, 379577741, 759155483, 1518310967, 379, 761, 1523, 3049, 6101, 12203, 24407, 48817,
97649, 195311, 390647, 781301, 1562611, 3125257, 6250537, 12501169, 25002389, 50004791, 100009607,
200019221, 400038451, 800076929, 1600153859 };
static {
Arrays.sort(primeCapacities);
}
}