I have an .nc file I'm reading in matlab, and getting info out of the time variable.
the code looks like this
>> ncreadatt(model_list{3},'T','units')
ans =
'months since 1850-01-01'
what I want to do is get just the '1850' out of the answer.
Regular expression is a very powerful tool to parse and manipulate strings.
Matlab has regexp command:
line = 'months since 1850-01-01';
res = regexp( line, '\s(\d+)-', 'tokens', 'once');
year = str2double(res{1})
And the results is:
year =
1850
The regular expression used '\s(\d+)-' means:
\s - look for a single white space character (the space before 1850).
'(\d+)' - look for one or more digit ('\d+'), the parentheses means that all charcters matching here will be saved as a "token".
'-' - look for a single '-' after the digits.
You can play with it on ideone.
String to Integer (atoi)
This problem is implement atoi to convert a string to an integer.
When test input = " +0 123"
My code return = 123
But why expected answer = 0?
======================
And if test input = " +0123"
My code return = 123
Now expected answer = 123
So is that answer wrong?
I think this is expected result as it said
Requirements for atoi:
The function first discards as many whitespace characters as necessary until the first non-whitespace character is found. Then, starting from this character, takes an optional initial plus or minus sign followed by as many numerical digits as possible, and interprets them as a numerical value.
Your first test case has a space in between two different digit groups, and atoi only consider the first group which is '0' and convert into integer
I have a any challenge. I must write brainfuck-code.
For a given number n appoint its last digit .
entrance
Input will consist of only one line in which there is only one integer n ( 1 < = n < = 2,000,000,000 ) , followed by a newline ' \ n' (ASCII 10).
exit
On the output has to find exactly one integer denoting the last digit of n .
example I
entrance: 32
exit: 2
example II:
entrance: 231231132
exit: 2
This is what I tried, but it didn't work:
+[>,]<.>++++++++++.
The last input is the newline. So you have to go two memory positions back to get the last digit of the number. And maybe you don't have to return a newline character, so the code is
,[>,]<<.
Nope sorry, real answer is
,[>,]<.
because your answer was getting one too far ;)
Depending on the interpreter, you might have to escape the return key by yourself. considering the return key is ASCII: 10, your code should look like this :
>,----- -----[+++++ +++++>,----- -----]<.
broken down :
> | //first operation (just in case your interpreter does not
support a negative pointer index)
,----- ----- | //first entry if it's a return; you don't even get in the loop
[
+++++ +++++ | //if the value was not ASCII 10; you want the original value back
>, | //every next entry
----- ----- | //check again for the the return,
you exit the loop only if the last entered value is 10
]
<. | //your current pointer is 0; you go back to the last valid entry
and you display it
Your issue is that a loop continues for forever until at the end of the loop the cell the pointer is currently on in equal to 0. Your code never prints in the loop, and never subtracts, so your loop will never end, and all that your code does is take an ASCII character as input, move one forward, take an ASCII character as input, and so on. All of your code after the end of the loop is useless, because that your loop will never end.
Instead of:
stringstream szBuffer;
szBuffer>>string;
myFunc(string);
How do I do like:
muFunc(szBuffer.NextString());
I dont want to create a temp var just for passing it to a function.
If you want to read the whole string in:
// .str() returns a string with the contents of szBuffer
muFunc(szBuffer.str());
// Once you've taken the string out, clear it
szBuffer.str("");
If you want to extract the next line (up to the next \n character), use istream::getline:
// There are better ways to do this, but for the purposes of this
// demonstration we'll assume the lines aren't longer than 255 bytes
char buf[ 256 ];
szBuffer.getline(buf, sizeof(buf));
muFunc(buf);
getline() can also take in a delimiter as a second parameter (\n by default), so you can read it word by word.
Please answer with the shortest possible source code for a program that converts an arbitrary plaintext to its corresponding ciphertext, following the sample input and output I have given below. Bonus points* for the least CPU time or the least amount of memory used.
Example 1:
Plaintext: The quick brown fox jumps over the lazy dog. Supercalifragilisticexpialidocious!
Ciphertext: eTh kiquc nobrw xfo smjup rvoe eth yalz .odg !uioiapeislgriarpSueclfaiitcxildcos
Example 2:
Plaintext: 123 1234 12345 123456 1234567 12345678 123456789
Ciphertext: 312 4213 53124 642135 7531246 86421357 975312468
Rules:
Punctuation is defined to be included with the word it is closest to.
The center of a word is defined to be ceiling((strlen(word)+1)/2).
Whitespace is ignored (or collapsed).
Odd words move to the right first. Even words move to the left first.
You can think of it as reading every other character backwards (starting from the end of the word), followed by the remaining characters forwards. Corporation => XoXpXrXtXoX => niaorCoprto.
Thank you to those who pointed out the inconsistency in my description. This has lead many of you down the wrong path, which I apologize for. Rule #4 should clear things up.
*Bonus points will only be awarded if Jeff Atwood decides to do so. Since I haven't checked with him, the chances are slim. Sorry.
Python, 50 characters
For input in i:
' '.join(x[::-2]+x[len(x)%2::2]for x in i.split())
Alternate version that handles its own IO:
print ' '.join(x[::-2]+x[len(x)%2::2]for x in raw_input().split())
A total of 66 characters if including whitespace. (Technically, the print could be omitted if running from a command line, since the evaluated value of the code is displayed as output by default.)
Alternate version using reduce:
' '.join(reduce(lambda x,y:y+x[::-1],x) for x in i.split())
59 characters.
Original version (both even and odd go right first) for an input in i:
' '.join(x[::2][::-1]+x[1::2]for x in i.split())
48 characters including whitespace.
Another alternate version which (while slightly longer) is slightly more efficient:
' '.join(x[len(x)%2-2::-2]+x[1::2]for x in i.split())
(53 characters)
J, 58 characters
>,&.>/({~(,~(>:#+:#i.#-#<.,+:#i.#>.)#-:)#<:##)&.><;.2,&' '
Haskell, 64 characters
unwords.map(map snd.sort.zip(zipWith(*)[0..]$cycle[-1,1])).words
Well, okay, 76 if you add in the requisite "import List".
Python - 69 chars
(including whitespace and linebreaks)
This handles all I/O.
for w in raw_input().split():
o=""
for c in w:o=c+o[::-1]
print o,
Perl, 78 characters
For input in $_. If that's not acceptable, add six characters for either $_=<>; or $_=$s; at the beginning. The newline is for readability only.
for(split){$i=length;print substr$_,$i--,1,''while$i-->0;
print"$_ ";}print $/
C, 140 characters
Nicely formatted:
main(c, v)
char **v;
{
for( ; *++v; )
{
char *e = *v + strlen(*v), *x;
for(x = e-1; x >= *v; x -= 2)
putchar(*x);
for(x = *v + (x < *v-1); x < e; x += 2)
putchar(*x);
putchar(' ');
}
}
Compressed:
main(c,v)char**v;{for(;*++v;){char*e=*v+strlen(*v),*x;for(x=e-1;x>=*v;x-=2)putchar(*x);for(x=*v+(x<*v-1);x<e;x+=2)putchar(*x);putchar(32);}}
Lua
130 char function, 147 char functioning program
Lua doesn't get enough love in code golf -- maybe because it's hard to write a short program when you have long keywords like function/end, if/then/end, etc.
First I write the function in a verbose manner with explanations, then I rewrite it as a compressed, standalone function, then I call that function on the single argument specified at the command line.
I had to format the code with <pre></pre> tags because Markdown does a horrible job of formatting Lua.
Technically you could get a smaller running program by inlining the function, but it's more modular this way :)
t = "The quick brown fox jumps over the lazy dog. Supercalifragilisticexpialidocious!"
T = t:gsub("%S+", -- for each word in t...
function(w) -- argument: current word in t
W = "" -- initialize new Word
for i = 1,#w do -- iterate over each character in word
c = w:sub(i,i) -- extract current character
-- determine whether letter goes on right or left end
W = (#w % 2 ~= i % 2) and W .. c or c .. W
end
return W -- swap word in t with inverted Word
end)
-- code-golf unit test
assert(T == "eTh kiquc nobrw xfo smjup rvoe eth yalz .odg !uioiapeislgriarpSueclfaiitcxildcos")
-- need to assign to a variable and return it,
-- because gsub returns a pair and we only want the first element
f=function(s)c=s:gsub("%S+",function(w)W=""for i=1,#w do c=w:sub(i,i)W=(#w%2~=i%2)and W ..c or c ..W end return W end)return c end
-- 1 2 3 4 5 6 7 8 9 10 11 12 13
--34567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
-- 130 chars, compressed and written as a proper function
print(f(arg[1]))
--34567890123456
-- 16 (+1 whitespace needed) chars to make it a functioning Lua program,
-- operating on command line argument
Output:
$ lua insideout.lua 'The quick brown fox jumps over the lazy dog. Supercalifragilisticexpialidocious!'
eTh kiquc nobrw xfo smjup rvoe eth yalz .odg !uioiapeislgriarpSueclfaiitcxildcos
I'm still pretty new at Lua so I'd like to see a shorter solution if there is one.
For a minimal cipher on all args to stdin, we can do 111 chars:
for _,w in ipairs(arg)do W=""for i=1,#w do c=w:sub(i,i)W=(#w%2~=i%2)and W ..c or c ..W end io.write(W ..' ')end
But this approach does output a trailing space like some of the other solutions.
For an input in s:
f=lambda t,r="":t and f(t[1:],len(t)&1and t[0]+r or r+t[0])or r
" ".join(map(f,s.split()))
Python, 90 characters including whitespace.
TCL
125 characters
set s set f foreach l {}
$f w [gets stdin] {$s r {}
$f c [split $w {}] {$s r $c[string reverse $r]}
$s l "$l $r"}
puts $l
Bash - 133, assuming input is in $w variable
Pretty
for x in $w; do
z="";
for l in `echo $x|sed 's/\(.\)/ \1/g'`; do
if ((${#z}%2)); then
z=$z$l;
else
z=$l$z;
fi;
done;
echo -n "$z ";
done;
echo
Compressed
for x in $w;do z="";for l in `echo $x|sed 's/\(.\)/ \1/g'`;do if ((${#z}%2));then z=$z$l;else z=$l$z;fi;done;echo -n "$z ";done;echo
Ok, so it outputs a trailing space.