HELP Newbie solve this Problem

Andrew Dalke dalke at acm.org
Sun Mar 26 13:45:54 CEST 2000


David Fisher gave a solution
>import string,operator;ldict={};map(lambda
>letter:operator.setitem(ldict,letter,0),map(chr,range(256)));map(lambda
>letter:operator.setitem(ldict,letter,ldict[letter]+1),open('data?').read())
;
>print string.join(map(lambda letter:letter+'
>'+`ldict[letter]`,string.lowercase),'\n')


Ahh, c'mon.  You can do better than that.  I count 279 characters
in that solution.  Here's one in one line and 167 characters
(with several bugs introduced since the original post did smell
like a homework problem):

exec "import string;v=[0]*26
for c in map(ord,string.lower(open('data').read())):
 if c >= 64 and c <= 89: v[c-64]=v[c-64]+1
for i in range(1,26):print chr(i+64),v[i]
"

Note that for Usenet purposes, I replaced the "\n" characters with
line breaks.  BTW, in spirit this is similar to the FORTRAN code,
since it doesn't use a dictionary for the values.

Or the more obscure but only making one full copy of the
data rather than the two above (via map(ord, ...) and string.lower)
here is a 216 byte solution with at least three introduced
bugs:

exec "import string;s=string;t=['@']*256
t[65:91]=t[96:122]=list(s.lowercase);v=[0]*27
for c in s.translate(open('data').read(),s.join(t,'')):
 v[ord(c)-64]=v[ord(c)-64]+1
for i in range(26):print chr(i+64),v[i]
"

Using the same tricks to your code yields 207 characters:

import string,operator;d={};s=string;t=operator.setitem;map(lambda
l:o(d,l,0),map(chr,range(256)));map(lambda
l:o(d,l,d[l]+1),open('data?').read());
print s.join(map(lambda l:l+' '+`d[l]`,s.lowercase),'\n')


Hmm, and using perl (again, there are bugs, some deliberate, but
I didn't even test a working solution first nor have I done much
perl programming in the last two years):

  perl -e 'open(F, ">>data");foreach (<F>) {\
            s/([a-zA-Z])/$d{lc($1)}++/ge } \
           foreach ("A".."Z"){print "$_ $d{$_}\n"}'

or about 127 characters.  The wonders of automatic hash creation
with automatic element creation with default values of 0.  And
of having a ++.  And a larger default library.  If I did the
file read right, it's line-at-a-time, so should also be less of
a memory hog than a full read() used in the Python examples.

                    Andrew
                    dalke at acm.org







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