Stack? (stack) is LIFO (last? Are you online? First of all? Off, LIFO) data structure.
The basic idea of the algorithm is: judge each character in the expression in turn. If it is a left parenthesis, put it on the stack; if it is a right parenthesis, judge whether it is empty; if it is empty, it means wrong; finally, when there is no character at the end of the expression, judge whether the stack is empty; if it is empty, it means matching; if it is not empty, it means mismatch.
Refer to the following code and address (/kkkkkxiaofei/article/details/8293980).
# Contains? & ltstdio.h & gt
# Contains? & ltmalloc.h & gt//malloc，realloc
# Contains? & ltmath.h & gt？ //contains overflow
# Contains? & ltprocess.h & gt？ //Exit ()
# Definition? S_SIZE？ 100// space size of the stack
# Definition? STACKINCREAMENT？ 10// Increase space
struct？ SQL stack {
int？ * base number; ? //Bottom of stack
int？ * top？ //stack top
int？ Stacksize// The current storage space of the stack.
};
Invalid? Master ()
{//Sub-function declaration
Invalid? InitStack(SqStack？ & amps)； //Initialize an empty stack
int？ StackEmpty(SqStack？ s)； //Empty sentence
Invalid? Push (SqStack? & amps，int？ e)； //into the stack
Invalid? pop(SqStack？ & amps，int？ & ampe)； //Exit the stack
//The start of the main function
SqStack？ s； //Initialize an empty stack
InitStack
Charles? ch[ 100]，* p； int？ e；
p = ch
Printf ("Enter a bracket expression, which means () [] {}: \ n");
gets(ch)；
while(*p)
{?
Switch? (*p)
{
Case? '{':
Case? '[':
Case? '(':? push(s，* p++)； Break; //As long as it is an opening parenthesis, it will be put on the stack.
Case? '}':
Case? ']':
Case? )’:pop(s，e)；
? What if? ((e=='{ '？ & amp& amp？ *p=='} ')？ ||(e=='['？ & amp& amp？ *p==']')？ ||? (e== '('？ & amp& amp？ *p== ')'))
? p++；
? other
? {printf ("Parentheses don't match!" ); Exit (overflow); }
? Break;
Default? :p++； //Other characters move backward.
}
}
What if? (Stack Properties)
Printf ("brackets match successfully");
other
Printf ("Missing closing bracket!" );
printf(" \ n ")；
}
Invalid? InitStack(SqStack？ & amps)
{S.base=(int？ *)malloc(S _ SIZE * sizeof(int))；
S.stacksize = S _ SIZE
s . top = s . base； //Initialize an empty stack
}
int？ StackEmpty(SqStack？ s)
{
if(S.base==S.top)
Return? 1;
other
Return? 0;
}
Invalid? Push (SqStack? & amps，int？ e)
{//Enter the stack
if(s . top-s . base & gt； =S.stacksize)
{S.base=(int？ *)realloc(S.base，(s . stack size+stack increament)* sizeof(int))；
s . top = s . base+s . stack size；
s . stack size+= stack increation； }
*(s . top)= e；
s . top++； ?
}
Invalid? pop(SqStack？ & amps，int？ & ampe)
{//Leave the stack
If (S.base! =S.top)
{ s . top-；
e = * S.top}
}