How do regular expression matching some punctuation marks must appear in pairs?-CodePudding

"" <> () {} [] (), types of punctuation in uncertain, but is a must in pairs,

"Childhood" practice questions (with answers) _ (founded baidu library)
"Childhood exercises (with answers) _ baidu library was not
"Childhood" exercises (including the answer _ baidu library was not
"Childhood" exercises [contain the answer] _ (baidu library was not
"Childhood" exercises [contain the answer] _ (baidu library) is founded

CodePudding user response:

Regular is not the best choice, it requires balance group, writing is not good maintenance, trouble
Used to analyze status code, as long as a few lines of code, faster,

 
The static bool IsBalanced (string input) 
{
Const string pairs="" "<> () {} [] () ". 
Var counters=new int [pairs. Length/2]; 
Input 
The Select (x=& gt; Pairs. IndexOf (x)) 
The Where (x=& gt; X & gt;=0) 
ToList () 
The ForEach (x=& gt; Counters/x/2 +=((x & amp; 1) * 2-1)); 
Return counters. The Sum ()==0; 
}

CodePudding user response:

correct (# 1) :
The static bool IsBalanced (string input)
{
.
Return couters. All (x=& gt; X==0) ;
}

CodePudding user response:

reference 1st floor github_36000833 response:

regular is not the best choice, it requires balance group, writing is not good maintenance, trouble
Used to analyze status code, as long as a few lines of code, faster,
 
The static bool IsBalanced (string input) 
{
Const string pairs="" "<> () {} [] () ". 
Var counters=new int [pairs. Length/2]; 
Input 
The Select (x=& gt; Pairs. IndexOf (x)) 
The Where (x=& gt; X & gt;=0) 
ToList () 
The ForEach (x=& gt; Counters/x/2 +=((x & amp; 1) * 2-1)); 
Return counters. The Sum ()==0; 
} 

According to tip the balance of above groups, from already groping, added some conditions, the line does not match the Spaces,,,, Such as

[^,,,,,?; "" "" <> () () () [] {} \ s] * (((? 'jxfinest' (" | | "" | | \ [| (| | ({) [^,,,,,?;" "" "<> () () () [] {} \ s] *) + ((? '- jxfinest' (" | | ">) | | \) | |]) |})) [^,,,,,?;" "" "<> () () () [] {} \ s] *) +) * (? ((jxfinest)? !). )

CodePudding user response:

reference jxfinest reply: 3/f

...
According to tip the balance of above groups, from already groping, added some conditions, the line does not match the Spaces,,,, Such as
.

Encourage and praise a,
Symbol if you want to match, you may use the more balance group, only total match, cannot solve the following input:

 "childhood library)

With regular purpose, is to make development easier, if found that regular more trouble, it is time to consider other way,

CodePudding user response:

reference 5 floor github_36000833 reply:

Quote: refer to the third floor jxfinest response:

.
According to tip the balance of above groups, from already groping, added some conditions, the line does not match the Spaces,,,, Such as
.

Encourage and praise a,
Symbol if you want to match, you may use the more balance group, only total match, cannot solve the following input:
"childhood library)

With regular purpose, is to make development easier, if found that regular more trouble, it is time to consider other practices,

You mentioned: "childhood library)
I remember I was considered the situation of ah, but there are no computer validation National Day go home in the car now, I am here is
(" | | ">) | | | | | \)])})
Rather than
[" ">) \])}]

CodePudding user response:

Verified, do exist github_36000833 described BUG

CodePudding user response:

Using multiple balance group, it is possible to each group of balance,

 (? X) # allow blank and comments 
^ 
(
[^ "" <> () {} [] ()] # does not contain special symbols 
| 
"(? ) | "(? <- dab>) # see "", the corresponding increase or decrease in dab (Double Angle Bracket) balance group 
| 
<(? ) |> (? <- ab>) 
| 
\ [(? ) | \] (? <- p>) 
| 
{(? ) |} (? <- cb>) 
| 
[(? & lt; sqb>) |] (? <- sqb>) 
| 
((? ) (|)? <- cnb>) 
) * 
(? ((dab)? !). Balance) # check Double Angle Bracket set allowance is not zero 
(? (ab)? !). ) # check the Angle Bracket balance group 
(? (p)? !). ) # check the Parenthesis balance group 
(? ((cb)? !). ) # check CurlyBrace balance group 
(? ((SQB)? !). ) # check SquareBracket balance group 
(? ((CNB)? !). ) # check CornerBracket balance group 
$

So that we can maintain a balance between each group, such as
"Childhood [exercises with answers]"

nevertheless, staggered match will be improved, which also can't judge the following cross match (if need strict matching) :
"Childhood [exercises with answers"]

In code is easier to control:

 class Program 
{
The static void Main (string [] args) 
{
Var b1=IsBalanced (" "childhood" exercises [contain the answer] _ (baidu library) set up ");//true 
Var b2=IsBalanced (" "" "" "" childhood" contain the solution [] (baidu library) "" "" "");//true 
Var b3=IsBalanced (library) "" childhood");//false 
Var b4=IsBalanced (" "childhood [exercises with answers"] ");//false; 
} 

The static bool IsBalanced (string input) 
{
Const string pairs="" "<> () {} [] () ". 
Var stack=new Stack (a); 
The foreach (char c in input) 
{
Int I=pairs. IndexOf (c); 
If (I==1) 
{
continue;//not symbolic, skip 
} 
If (I % 2==0) 
{
Stack. Push (c);//even as symbolic open, into the stack 
} 
End the else//odd for symbols, check the top of the stack must be matched 'symbol' 
{
If (stack. Count==0 | | stack. Pop ()!=pairs] [I - 1) 
{
return false; 
} 
} 
} 
The return stack. Count==0;//all pairs must complete 
} 
}