Helsing

A mostly POSIX-compliant utility that scans a given interval for vampire numbers.

In helsing/configuration.h you can select the algorithm implementation and tune it, adjust verbosity, change the numeral base system, set a minimum fang pairs filter, and enable resume from checkpoint. Be sure to read the documentation.

Windows isn't posix compatible. You'll need to install WSL and a linux distribution from the Windows Store.

Dependencies

• a C compiler (clang or gcc should do just fine)

• GNU make

• findutils

• OpenSSL (optional)

  Platform	Package name
  Debian	libssl-dev
  Fedora/RHEL	openssl-devel
  FreeBSD	openssl-devel
  HaikuOS	(pre-installed)
  Homebrew	openssl
  Openindiana	library/security/openssl-11

Download

git clone https://github.com/plerros/helsing.git
cd helsing

Compile

GNU/Linux, HaikuOS, Homebrew, WSL

cd helsing
make

FreeBSD, OpenIndiana

cd helsing
gmake

Run

./helsing -l min -u max

Examples:

$ ./helsing -l 1260 -u 1260
Checking interval: [1260, 1260]
Found: 1 vampire number(s).

$ ./helsing -l 0 -u 1172560176
Adjusted min from 0 to 10
Checking interval: [10, 99]
Checking interval: [1000, 9999]
Checking interval: [100000, 999999]
Checking interval: [10000000, 99999999]
Checking interval: [1000000000, 1172560176]
Found: 10000 vampire number(s).

$ ./helsing -l 18446744073709551615 -u 18446744073709551615
Checking interval: [18446744073709551615, 18446744073709551615]
Found: 0 vampire number(s).

Run for all n-digit numbers

./helsing -n number_of_digits

Examples:

$ ./helsing -n 2
Checking interval: [10, 99]
Found: 0 vampire number(s).

$ ./helsing -n 4
Checking interval: [1000, 9999]
Found: 7 vampire number(s).

$ ./helsing -n 12
Checking interval: [100000000000, 999999999999]
Found: 4390670 vampire number(s).

Set the number of threads

./helsing -t threads

Examples:

$ time ./helsing -n 12 -t 1
Checking interval: [100000000000, 999999999999]
Found: 4390670 vampire number(s).

real	0m39.360s
user	0m39.294s
sys 	0m0.010s

$ time ./helsing -n 12 -t 2
Checking interval: [100000000000, 999999999999]
Found: 4390670 vampire number(s).

real	0m20.036s
user	0m39.746s
sys 	0m0.022s

$ time ./helsing -n 12 -t 4
Checking interval: [100000000000, 999999999999]
Found: 4390670 vampire number(s).

real	0m10.514s
user	0m41.624s
sys 	0m0.022s

Display progress

./helsing --progress

Example:

$ ./helsing -n 12 --progress
Checking interval: [100000000000, 999999999999]
100000000000, 199999999999  1/9
200000000000, 299999999999  2/9
300000000000, 399999999999  3/9
400000000000, 499999999999  4/9
500000000000, 599999999999  5/9
600000000000, 699999999999  6/9
700000000000, 799999999999  7/9
800000000000, 899999999999  8/9
900000000000, 999998000001  9/9
Found: 4390670 vampire number(s).

Display build configuration

./helsing --buildconf

Example:

$ ./helsing --buildconf
  configuration:
    VERBOSE_LEVEL=2
    MIN_FANG_PAIRS=1
    MEASURE_RUNTIME=false
    CACHE=true
    COMPARISON_BITS=64
    DEDICATED_BITFIELDS=false
    USE_PDEP=false
    BASE=10
    MAX_TASK_SIZE=99999999999
    USE_CHECKPOINT=false
    LINK_SIZE=100
    SANITY_CHECK=false

Recover from checkpoint (if enabled in configuration)

./helsing