Brilliant numbers: Difference between revisions
Content added Content deleted
(added python) |
(→{{header|Python}}: change to numpy for efficiency) |
||
Line 933: | Line 933: | ||
=={{header|Python}}== |
=={{header|Python}}== |
||
Using primesieve and numpy modules |
|||
<lang Python>from primesieve.numpy import primes |
<lang Python>from primesieve.numpy import primes |
||
from math import isqrt |
|||
import numpy as np |
|||
max_order = 9 |
max_order = 9 |
||
primes = [primes(10**n, 10**(n + 1)) for n in range(max_order)] |
|||
def smallest_brilliant( |
def smallest_brilliant(lb): |
||
pos = 1 |
pos = 1 |
||
root = isqrt(lb) |
|||
⚫ | |||
⚫ | |||
for blk in primes: |
|||
⚫ | |||
if blk[-1]*blk[-1] < lb: |
|||
pos += n*(n + 1)//2 |
pos += n*(n + 1)//2 |
||
continue |
continue |
||
i = np.searchsorted(blk, root, 'left') |
|||
i += blk[i]*blk[i] < lb |
|||
if (prod := p*p) >= thresh: |
|||
if not i: |
|||
return blk[0]*blk[0], pos |
|||
⚫ | |||
⚫ | |||
idx = np.searchsorted(blk, q, 'right') |
|||
sel = idx < n |
|||
p, idx = p[sel], idx[sel] |
|||
q = blk[idx] |
|||
⚫ | |||
⚫ | |||
⚫ | |||
sel = q >= p |
|||
p, q, idx = p[sel], q[sel], idx[sel] |
|||
best = min(best, prod) |
|||
pos += np.sum(idx - np.arange(len(idx))) |
|||
return |
return np.min(p*q), pos |
||
res = [] |
|||
p = 0 |
|||
for i in range(100): |
for i in range(100): |
||
p, |
p, _ = smallest_brilliant(p + 1) |
||
res.append(p) |
|||
print(f' |
print(f'first 100 are {res}') |
||
for |
for i in range(max_order*2): |
||
thresh = 10**i |
|||
p, pos = smallest_brilliant(thresh) |
|||
print(f' |
print(f'Above 10^{i:2d}: {p:20d} at #{pos}')</lang> |
||
{{out}} |
{{out}} |
||
<pre> |
<pre>first 100 are [4, 6, 9, 10, 14, 15, 21, 25, 35, 49, 121, 143, 169, 187, 209, 221, 247, 253, 289, 299, 319, 323, 341, 361, 377, 391, 403, 407, 437, 451, 473, 481, 493, 517, 527, 529, 533, 551, 559, 583, 589, 611, 629, 649, 667, 671, 689, 697, 703, 713, 731, 737, 767, 779, 781, 793, 799, 803, 817, 841, 851, 869, 871, 893, 899, 901, 913, 923, 943, 949, 961, 979, 989, 1003, 1007, 1027, 1037, 1067, 1073, 1079, 1081, 1121, 1139, 1147, 1157, 1159, 1189, 1207, 1219, 1241, 1247, 1261, 1271, 1273, 1333, 1343, 1349, 1357, 1363, 1369] |
||
⚫ | |||
611, 629, 649, 667, 671, 689, 697, 703, 713, 731, 737, 767, 779, 781, 793, 799, 803, 817, 841, 851, 869, 871, 893, 899, 901, 913, 923, 943, 949, 961, 979, 989, 1003, 1007, 1027, 1037, 1067, 1073, 1079, 10 |
|||
Above 10^ 1: 10 at #4 |
|||
81, 1121, 1139, 1147, 1157, 1159, 1189, 1207, 1219, 1241, 1247, 1261, 1271, 1273, 1333, 1343, 1349, 1357, 1363, 1369] |
|||
⚫ | |||
first above 10** 0: 4 at position 1 |
|||
Above 10^ 3: 1003 at #74 |
|||
first above 10** 1: 10 at position 4 |
|||
Above 10^ 4: 10201 at #242 |
|||
first above 10** 2: 121 at position 11 |
|||
Above 10^ 5: 100013 at #2505 |
|||
first above 10** 3: 1003 at position 74 |
|||
Above 10^ 6: 1018081 at #10538 |
|||
first above 10** 4: 10201 at position 242 |
|||
Above 10^ 7: 10000043 at #124364 |
|||
first above 10** 5: 100013 at position 2505 |
|||
Above 10^ 8: 100140049 at #573929 |
|||
first above 10** 6: 1018081 at position 10538 |
|||
Above 10^ 9: 1000000081 at #7407841 |
|||
first above 10** 7: 10000043 at position 124364 |
|||
Above 10^10: 10000600009 at #35547995 |
|||
first above 10** 8: 100140049 at position 573929 |
|||
Above 10^11: 100000000147 at #491316167 |
|||
first above 10** 9: 1000000081 at position 7407841 |
|||
Above 10^12: 1000006000009 at #2409600866 |
|||
first above 10**10: 10000600009 at position 35547995 |
|||
Above 10^13: 10000000000073 at #34896253010 |
|||
first above 10**11: 100000000147 at position 491316167 |
|||
Above 10^14: 100000380000361 at #174155363187 |
|||
first above 10**12: 1000006000009 at position 2409600866 |
|||
Above 10^15: 1000000000000003 at #2601913448897 |
|||
first above 10**13: 10000000000073 at position 34896253010 |
|||
Above 10^16: 10000001400000049 at #13163230391313 |
|||
first above 10**14: 100000380000361 at position 174155363187 |
|||
Above 10^17: 100000000000000831 at #201431415980419</pre> |
|||
first above 10**15: 1000000000000003 at position 2601913448897 |
|||
first above 10**16: 10000001400000049 at position 13163230391313 |
|||
first above 10**17: 100000000000000831 at position 201431415980419 </pre> |
|||
=={{header|Raku}}== |
=={{header|Raku}}== |