11105 - Semi-prime H-numbers

coolguy · Post by **coolguy** » Tue Oct 17, 2006 6:04 pm

according to my code the number of H primes in the range is 89070 and number of H semi primes is 117965 ........am i right ?? can anyone please verify .............
waiting to be helped ....

david · Post by **david** » Thu Oct 19, 2006 1:37 am

There are 89070 h-primes and 105753 h semi-primes in the range allowed.

coolguy · Post by **coolguy** » Fri Oct 20, 2006 7:16 am

thank u david for ur reply . i got it ac . i was counting repeats . now i maintain a set and get ac ..
bye bye

cytmike · Post by **cytmike** » Fri Nov 03, 2006 4:34 am

Anybody knows a more efficient way to do this?
My code gets AC in 9.97s ....

helloneo · Post by **helloneo** » Fri Nov 03, 2006 4:58 pm

cytmike wrote:Anybody knows a more efficient way to do this?
My code gets AC in 9.97s ....

I did something like sieve..
It runs 0.104 sec..

chinmoy kanti dhar · Post by **chinmoy kanti dhar** » Thu Jun 28, 2007 12:30 am

how can i determine a H prime.Is 49 is a H prime?plz help me by giving first 20 H prime.....

Jan · Post by **Jan** » Thu Jun 28, 2007 1:34 pm

chinmoy kanti dhar wrote: 1. how can i determine a H prime. Is 49 is a H prime?
2. plz help me by giving first 20 H prime.....

1. Modified sieve will do.

2. The first 20 Hprime are...

Code: Select all

5 9 13 17 21 29 33 37 41 49 53 57 61 69 73 77 89 93 97 101

Hope these help.

jainal cse du · Post by **jainal cse du** » Wed Aug 01, 2007 12:16 pm

Code: Select all

Yes, Now I got AC.
code removed

lucky16g · Post by **lucky16g** » Tue Oct 16, 2007 5:14 pm

for sample input
789
i got ans 64
follower are my 64 H-semi-primes
can anyone tell me which two are not H-semi-primes
1 ) 5 5 =25
2 ) 5 9 =45
3 ) 5 13 =65
4 ) 5 17 =85
5 ) 5 21 =105
6 ) 5 29 =145
7 ) 5 33 =165
8 ) 5 37 =185
9 ) 5 41 =205
10 ) 5 49 =245
11 ) 5 53 =265
12 ) 5 57 =285
13 ) 5 61 =305
14 ) 5 69 =345
15 ) 5 73 =365
16 ) 5 77 =385
17 ) 5 89 =445
18 ) 5 93 =465
19 ) 5 97 =485
20 ) 5 101 =505
21 ) 5 109 =545
22 ) 5 113 =565
23 ) 5 121 =605
24 ) 5 129 =645
25 ) 5 133 =665
26 ) 5 137 =685
27 ) 5 141 =705
28 ) 5 149 =745
29 ) 5 157 =785
30 ) 9 9 =81
31 ) 9 13 =117
32 ) 9 17 =153
33 ) 9 21 =189
34 ) 9 29 =261
35 ) 9 33 =297
36 ) 9 37 =333
37 ) 9 41 =369
38 ) 9 49 =441
39 ) 9 53 =477
40 ) 9 57 =513
41 ) 9 61 =549
42 ) 9 69 =621
43 ) 9 73 =657
44 ) 9 77 =693
45 ) 13 13 =169
46 ) 13 17 =221
47 ) 13 21 =273
48 ) 13 29 =377
49 ) 13 33 =429
50 ) 13 37 =481
51 ) 13 41 =533
52 ) 13 49 =637
53 ) 13 53 =689
54 ) 13 57 =741
55 ) 17 17 =289
56 ) 17 21 =357
57 ) 17 29 =493
58 ) 17 33 =561
59 ) 17 37 =629
60 ) 17 41 =697
61 ) 21 21 =441
62 ) 21 29 =609
63 ) 21 33 =693
64 ) 21 37 =777

Jan · Post by **Jan** » Wed Oct 17, 2007 2:14 am

You are counting 441 and 693 twice!

lucky16g · Post by **lucky16g** » Wed Oct 17, 2007 6:06 am

thanks for your debug
there's very helfull for me
thanks a lot!!!

lnr · Post by **lnr** » Mon Aug 04, 2008 3:51 pm

5=5*1 so it is not a semi prime.
1 is unit.

lnr · Post by **lnr** » Mon Aug 04, 2008 7:07 pm

What is the difference between H-primes and H-semi-primes?

sazzadcsedu · Post by **sazzadcsedu** » Tue Feb 17, 2009 9:56 pm

how to determine a particular number is only multiple of 2 number!!!
plz some give me some idea;
i remove number containing more than 2-(5,9,13,17.....)
but cant handle case like:-5*117=(5*9*17).
how to handle them?????

helloneo · Post by **helloneo** » Wed Feb 18, 2009 4:36 pm

You can try a similar but little bit easier problem..

http://icpcres.ecs.baylor.edu/onlinejud ... 10856.html

If you don't know about factorization very well, there are also good problems to learn it..

http://icpcres.ecs.baylor.edu/onlinejud ... 1/160.html
http://icpcres.ecs.baylor.edu/onlinejud ... 5/583.html
http://icpcres.ecs.baylor.edu/onlinejud ... 10699.html

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