User:Yeti
Contents
AWK/Primes/FSOE[edit]
AWK/Primes/FSOE1[edit]
FSOE1 needs a number:set mapping and expressing this in AWK would blow up the code too much. (Or shorter: Maybe later.)
AWK/Primes/FSOE3[edit]
BEGIN {
n=2
while( n<100 ) {
if( n in L ) {
p=L[n]
del L[n]
} else {
p=n
printf n " "
}
npp=n+p
while( npp in L )
npp=npp+p
L[npp]=p
n++
}
}
- Output:
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97
BASH/Self Modyfying Code[edit]
$ . Thing-1033909978 $ type Thing Thing is a function Thing () { local get='shift;local __=$1;shift;echo ${!__}' set='shift;__=$1;shift;local $__="$*";eval "$FUNCNAME () { local $(local | tr "\n" " "); $(type $FUNCNAME | tail +5)"' version=1033909978; eval ${!1} } $ Thing get version 1033909978 $ date [email protected]$(Thing get version) # ;-) Sun Oct 6 13:12:58 UTC 2002 $ ## $ ## add a new property 'show' $ ## $ Thing set show local $ ## $ ## try it $ ## $ Thing show get='shift;local __=$1;shift;echo ${!__}' set='shift;__=$1;shift;local $__="$*";eval "$FUNCNAME () { local $(local | tr "\n" " "); $(type $FUNCNAME | tail +5)"' show=local version=1033909978
Dc/Questions/DROP[edit]
TODO Drop top of stack without side effects
# assume there is a value in x[1337], e.g. "gold" [gold] 1337 :x # "trash" on the stack: [trash] # push x[1337] to x-stack 1337;x Sx # deposit TOS in x[1337] 1337: # top of x-stack to x[1337] Lx 1337: 1337 ;x [Stack: ]PAP f
- Output:
Stack: gold
Sigh!
Is there really no simpler way to drop the top of stack that works for strings and numbers and in all versions of Dc?
Python/Primes/FSOE[edit]
This is a sequentialised variant of the well known sieve method (ab)using a dictionary as sparse array.
Alternatively you can describe it as finding the wheels and moving them on a tape. The only knowledge is to start looking 2 instead of starting with 1, but the original sieve does skip 1 too. 2 is not hard coded to be prime. The algorithm detects it as 1st prime and then puts the 2-wheel on the tape.
Python/Primes/FSOE1[edit]
Variant: A tape position can hold multiple wheels.
L = {}
n = 2
while 1:
if n in L:
P = L[n]
del L[n] # optional - saves some memory.
else:
print n
P = [n]
for p in P:
npp = n+p
if npp in L:
L[npp].add(p)
else:
L[npp] = set([p])
n += 1
- Output:
2 3 5 7 11 13 17 19 23 29
...the program has to be terminated by the user e.g. by typing ctrl-c.
Python/Primes/FSOE3[edit]
Variant: A tape position can hold one wheel.
L = {}
n = 2
while 1:
if n in L:
P = L[n]
del L[n] # optional - saves some memory.
else:
P = n
print n
m = n+P
while m in L:
m += P
L[m] = P
n += 1
- Output:
2 3 5 7 11 13 17 19 23 29
...the program has to be terminated by the user e.g. by typing ctrl-c.
My Favorite Languages | |
Language | Proficiency |
AWK | --- |
B | --- |
BASH | --- |
C | --- |
Dc | --- |
Spin | --- |