Tài liệu Data structures algorithms in java

Matching Parentheses and HTML Tags
In this subsection, we explore two related applications of stacks, the first of which
is for matching parentheses and grouping symbols in arithmetic expressions.
Arithmetic expressions can contain various pairs of grouping symbols, such as
ã Parentheses: ( and )
ã Braces: { and }
ã Brackets: [ and ]
ã Floor function symbols:  and 
ã Ceiling function symbols:  and ,
and each opening symbol must match with its corresponding closing symbol. For
example, a left bracket, [, must match with a corresponding right bracket, ], as
in the following expression:
[(5 + x) ư (y + z)]