Python 3370
Ich wollte, dass dies so gut wie möglich funktioniert, und brachte sogar Abwechslung zum Laufen (mit korrekter Überprüfung der Doppelzählung!). Soweit ich weiß, funktioniert das für alles außer für Lookarounds (weil das verrückt wäre).
Wenn Sie eine eigene Lösung schreiben, können Sie meine Methoden nach Belieben anwenden / verbessern.
Code:
R=range;L=len;E=enumerate;I=int;F="Infinity";S=sum;H=chr;D=ord;J=lambda l:''.join(l);U=lambda s:J([H(i)if H(i) not in s else''for i in R(1,128)]);s=' \n\t';c=J((H(i)if H(i)not in s else'')for i in R(1,32));d,l,u=[J(H(i)for i in R(*n))for n in [[48,59],[97,123],[65,91]]];p='`~!@#$%^&*()-_=+[{]}\\|;:\'",<.>/?';Y={'\\s':s,'\\S':c+s+p+u+l+d,'\\d':d,'\\D':U(d),'\\w':u+l+'_','\\W':U(u+l+'_'),'[:alnum:]':u+l+d,'[:alpha:]':u+l,'[:ascii:]':U(''),'[:blank:]':' \t','[:cntrl:]':c,'[:digit:]':d,'[:graph:]':p+d+l+u,'[:lower:]':l,'[:print:]':p+d+l+u+s,'[:punct:]':p,'[:space:]':s,'[:upper:]':u,'[:word:]':l+u+'_','[:xdigit:]':d+'ABCDEF'};C=lambda l,n:[d+[l[i]]for i in R(L(l))for d in C(l[i+1:],n-1)]if n>0 else[[]];O=lambda x:S([all((c in s)for s in [(e[1]if any(e[1] not in Y for e in x)else Y[e[1]])if e[0]=='e'else(e[1]if e[0]=='t'else((Y[e[1]]if e[1]in Y else B(e[1]))if e[0]=='['else''))for e in x])for c in Y['[:ascii:]']])
def X(r):
x=[];l=0;c=''
for h in r:
l+=I(h in'([')-I(h in')]')
if l<1 and'|'==h:x+=[c];c=''
else:c+=h
x+=[c]
if L(x)>1:
o=0;m=[];u=[]
for e in x:
p,b=X(e)
if p==F:return F,[]
o+=p;m+=[('(',b)];u+=[b]
return o-S([(-1)**(i%2)*T(s) for i in R(2,L(u)+1)for s in C(u,i)]),[('|',m)]
u=[];o=[];m=[];w=1
while r!='':
h=r[0];z=0
if h in'([{':
l=1;i=1
while l>0:k=r[i];l+=(k==h)-(k=={'(':')','[':']','{':'}'}[h]);i+=1
u+=[(h,r[1:i-1])];z=i
elif h=='\\':u+=[('e','\\'+eval("'\\%s'"%r[1]))]if r[1]in'nt'else[('e','\\'+r[1])];z=2
elif h in ['*','+','?']:u+=[('{',h)];z=1
elif h in'^$':return 0
elif h=='.':u+=[('[','[:ascii:]')];z=1
else:u+=[('t',h)];z=1
r=r[z:]
for t,g in u:
if t=='(':p,b=X(g);o+=[p];m+=[('(',b)]
elif t=='e':o+=[L(Y[g])]if g in Y else[1]
elif t=='[':o+=[N(g)]
elif t=='{':
n=o[-1]
try:o[-1]=S([n**r for r in Q(g)])
except:return F,[]
elif t=='t':o+=[1]
if t!='(':m+=[(t,g)]
for c in o:
if c==F:return F,[]
w*=c
return w,m
def N(s):
if s in Y:return L(Y[s])
if(s[0],s[-1])==('[',']'):return 1
n=(s[0]=='^');a=0
if n:s=s[1:]
while s!='':
if L(s)>=3 and s[1]=='-':a+=D(s[2])-D(s[0])+1;s=s[3:];continue
a+=1;s=s[1:]
return 256*n+(-1)**n*a
def Q(s):
if s=='?':return[0,1]
if s[0]in'*+':return None
if ','in s:
l,h=s.split(',')
return None if h==''else R(I(l),I(h)+1)
return[I(s)]
def B(s):
n=(s[0]=='^')
if n:s=s[1:]
a='';w=''
while s!='':
h=s[0]
if 3<=L(s)and'-'==s[1]:
for i in R(D(s[0]),D(s[2])+1):a+=H(i)
s=s[3:];continue
a+=h;s=s[1:]
return J([c*(c not in a)for c in Y['[:ascii:]']])if n else a
def T(x):
if all(e==[] for e in x):return 1
for i,e in E(x):
if L(e)>=2 and e[1][0]=='{':return S([T([[e[0]]*n+e[2:]]+x[:i]+x[i+1:])for n in Q(e[1][1])])
if L(e)>=1:
if e[0][0] == '(':return T([e[0][1]+e[1:]]+x[:i]+x[i+1:])
if e[0][0]== '|':
t=S(T([[s]+e[1:]]+x[:i]+x[i+1:])for s in e[0][1])
u=[[s]for s in e[0][1]]
return t-S((-1)**(j%2)*T(b)for j in R(2,L(u)+1)for b in C(u,j))
if any(e==[]for e in x):return 0
return O([e[0]for e in x])*T([e[1:]for e in x])
r=raw_input();e=[];l=0;c=''
for h in r:
l+=I(h in'([')-I(h in')]')
if l<1 and'|'==h:e+=[c];c=''
else:c+=h
e+=[c];o=[];x=[]
for f in e:
if '^'!=f[0]or'$'!=f[-1]:print F;quit()
n,m=X(f[1:-1])
if n==F:print F;quit()
o+=[n];x+=[m]
print S(o)-S([(-1)**(i%2)*T(s) for i in R(2,L(x)+1)for s in C(x,i)])
Ungolfed:
controlchars = ''
for i in range(1,32):
if chr(i) not in '\t\n':
controlchars += chr(i)
CLASSES={
'\\s':' \t\n',
'\\S':controlchars+'!"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~',
'\\d':'0123456789',
'\\D':controlchars+'\n\t !"#$%&\'()*+,-./:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~',
'\\w':'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_',
'\\W':controlchars+'\n\t !"#$%&\'()*+,-./:;<=>?@[\\]^`{|}~',
'[:alnum:]':'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789',
'[:alpha:]':'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',
'[:ascii:]':controlchars+'\n\t !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~',
'[:blank:]':' \t',
'[:cntrl:]':controlchars,
'[:digit:]':'0123456789',
'[:graph:]':'!"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~',
'[:lower:]':'abcdefghijklmnopqrstuvwxyz',
'[:print:]':'\n\t !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~',
'[:punct:]':'`~!@#$%^&*()-_=+[{]}\\|;:\'",<.>/?',
'[:space:]':' \t\n',
'[:upper:]':'ABCDEFGHIJKLMNOPQRSTUVWXYZ',
'[:word:]':'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_',
'[:xdigit:]':'0123456789ABCDEF'
}
DELIMIT = {
'(':')',
')':'(',
'[':']',
']':'[',
'{':'}',
'}':'{'
}
def combos(lst,num):
if num == 0:
return [[]]
combs = []
for i in range(len(lst)):
for c in combos(lst[i+1:],num-1):
combs.append([lst[i]]+c)
return combs
def count_regex(regex):
exprs = []
level = 0
current = ''
for char in regex:
if char in '([':
level += 1
if char in ')]':
level -= 1
if char == '|' and level == 0:
exprs.append(current)
current = ''
else:
current += char
exprs.append(current)
comps = []
expanded = []
for e in exprs:
if (e[0] != '^' or e[-1] != '$'):
return 'Infinity'
num,member = count_expr(e[1:-1])
if num == 'Infinity':
return 'Infinity'
comps.append(num)
expanded.append(member)
total = sum(comps)
for i in range(2,len(expanded)+1):
for subset in combos(expanded,i):
if i % 2 == 0:
total -= count_doubles(subset)
else:
total += count_doubles(subset)
return total
def count_expr(expr):
exprs = []
level = 0
current = ''
for char in expr:
if char in '([':
level += 1
if char in ')]':
level -= 1
if char == '|' and level == 0:
exprs.append(current)
current = ''
else:
current += char
exprs.append(current)
if len(exprs) != 1:
comps = 0
members = []
sub = []
for e in exprs:
comp,memb = count_expr(e)
if comp == 'Infinity':
return 'Infinity',[]
comps += comp
members.append(('(',memb))
sub.append(memb)
for i in range(2,len(sub)+1):
for subset in combos(sub,i):
if i % 2 == 0:
comps -= count_doubles(subset)
else:
comps += count_doubles(subset)
return comps,[('|',members)]
sub = []
while expr != '':
char = expr[0]
if char in ['(','[','{']:
level = 1
i = 1
while level > 0:
nchar = expr[i]
if nchar == char: level += 1
if nchar == DELIMIT[char]: level -= 1
i += 1
sub.append((char,expr[1:i-1]))
expr = expr[i:]
elif char == '\\':
if expr[1] == 'n':
sub.append(('e','\\'+'\n'))
expr = expr[2:]
elif expr[1] == 't':
sub.append(('e','\\'+'\t'))
expr = expr[2:]
else:
sub.append(('e','\\'+expr[1]))
expr = expr[2:]
elif char in ['*','+','?']:
sub.append(('{',char))
expr = expr[1:]
else:
if char in '^$':
return 0
if char == '.':
sub.append(('[','[:ascii:]'))
expr = expr[1:]
else:
sub.append(('t',char))
expr = expr[1:]
components = []
members = []
for t,string in sub:
if t == '(':
comp,memb = count_expr(string)
components.append(comp)
members.append(('(',memb))
elif t == 'e':
if string in CLASSES:
components.append(len(CLASSES[string]))
else:
components.append(1)
elif t == '[':
components.append(count_class(string))
elif t == '{':
num = components[-1]
try:
components[-1] = sum([num**r for r in count_quantifier(string)])
except TypeError:
return 'Infinity',[]
elif t == 't':
components.append(1)
if t != '(':
members.append((t,string))
total = 1
for c in components:
if c == 'Infinity':
return 'Infinity',[]
total *= c
return total,members
def count_class(string):
if string in CLASSES:
return len(CLASSES[string])
if string[0] == '[' and string[-1] == ']':
return 1
negate = (string[0] == '^')
if negate: string = string[1:]
avail_count = 0
while string != '':
char = string[0]
if len(string) >= 3:
if string[1] == '-':
first,last = string[0],string[2]
avail_count += ord(last)-ord(first)+1
string = string[3:]
continue
avail_count += 1
string = string[1:]
if negate:
return 256-avail-count
return avail_count
def count_quantifier(string):
if string == '?':
return [0,1]
if string[0] in '*+':
return None
if ',' in string:
low,high = string.split(',')
if high == '':
return None
return range(int(low),int(high)+1)
return [int(string)]
def bracket_string(string):
negate = (string[0] == '^')
if negate: string = string[1:]
avail = ''
while string != '':
char = string[0]
if len(string) >= 3:
if string[1] == '-':
first,last = string[0],string[2]
for i in range(ord(first),ord(last)+1):
avail += chr(i)
string = string[3:]
continue
avail += char
string = string[1:]
if negate:
new = ''
for c in CLASSES['[:ascii:]']:
if c not in avail:
new += c
return new
return avail
def overlap(es):
chars=['' for i in range(len(es))]
for i,e in enumerate(es):
if e[0] == 'e':
if any(e[1] not in CLASSES for e in es):
chars[i] = e[1]
else:
chars[i] = CLASSES[e[1]]
for i,e in enumerate(es):
if e[0] == 't':
chars[i] = e[1]
for i,e in enumerate(es):
if e[0] == '[':
if e[1] in CLASSES:
chars[i] = CLASSES[e[1]]
else:
chars[i] = bracket_string(e[1])
total = 0
for c in CLASSES['[:ascii:]']:
has = True
for chs in chars:
if c not in chs:
has = False
break
if has:
total += 1
return total
def count_doubles(exprs):
if all(e==[] for e in exprs):
return 1
for i,expr in enumerate(exprs):
if len(expr) >= 2 and expr[1][0] == '{':
rng = count_quantifier(expr[1][1])
total = 0
for n in rng:
total += count_doubles([ [expr[0]]*n+expr[2:] ] + exprs[:i] + exprs[i+1:])
return total
for i,expr in enumerate(exprs):
if len(expr) >= 1 and expr[0][0] == '(':
return count_doubles([ expr[0][1]+expr[1:] ] + exprs[:i] + exprs[i+1:] )
if any(e==[] for e in exprs):
return 0
for i,expr in enumerate(exprs):
if expr[0][0] == '|':
total = 0
subs = []
for sub_expr in expr[0][1]:
subs.append([sub_expr])
total += count_doubles([ [sub_expr]+expr[1:] ] + exprs[:i] + exprs[i+1:])
for j in range(2,len(subs)+1):
for subset in combos(subs,j):
if j % 2 == 0:
total -= count_doubles(subset)
else:
total += count_doubles(subset)
return total
over = overlap([e[0] for e in exprs])
if over == 0:
return 0
return over * count_doubles([e[1:] for e in exprs])
reg = raw_input('Regex: ')
print count_regex(reg)
Hier sind einige relevante Testfälle, die ich bestätigt habe:
Regex: ^[A-Za-z0-9]{8}$
218340105584896
Regex: ^([a-b]*)$
Infinity
Regex: ^([0-9]|[a-e])([a-e]|[A-E])$|^[a-f]{2}$
161
Regex: ^[a-z]{2}$|^[0-9]?[a-z]{2,3}$|^a[a-z]?$
200773
Regex: ^([a-z]|[a-e]|[A-E]|[3-4]|[D-G])$
35
Regex: ^\(.)\(.)\2\1$
16129*
Regex: ^(a)\1?$
2
Regex: ^[[:space:]]$|^\t$
3
* Dies ist bei Golfspielern und Nicht-Golfspielern tatsächlich anders, da es einen Unterschied von einem Zeichen bei den als gültig definierten Ascii gibt. Ich glaube, der Golfspieler ist der Richtigere.
Um zu bestätigen, dass weitere Tests durchgeführt werden konnten, teilen Sie mir bitte alle Fehler mit (ich wäre ehrlich gesagt nicht überrascht, wenn es nicht wenige gäbe).
^[A-Za-z0-9]{8}$? Sonst wäre die Antwortinfinity.