括号匹配（C语言）

#include<stdio.h>
#include<stdlib.h>
#define Max 100
typedef char datetype;
typedef struct{
    datetype c[Max];
    int top;
}sequence_stack;
void init(sequence_stack* s)
{
    s->top=0;
}
int empty(sequence_stack s)
{
    return (s.top?0:1);
}
datetype read(sequence_stack s)
{
    return s.c[s.top-1];
}
void push(sequence_stack* s,datetype x)
{
    if(s->top==Max)
    {
        printf("The sequence stack is full!\n");
        exit(1);
    }
    s->c[s->top++]=x;
}
void pop(sequence_stack* s)
{
    s->top--;
}
int parenthesis_matching(char c[])
{
    sequence_stack s;
    init(&s);
    int i=0;
    while(c[i]!='#')
    {
        switch(c[i])
        {
            case '{':
            case '[':
            case '(':
                        push(&s,c[i]);
                        break;
            case '}':
                        if(!empty(s)&&read(s)=='{')
                            {
                                pop(&s);break;
                            }
                        else 
                            return 0;
            case ']':
                        if(!empty(s)&&read(s)=='[')
                            {
                                pop(&s);break;
                            }
                        else return 0;
             case ')':
                        if(!empty(s)&&read(s)=='(')
                            {
                                pop(&s);break;
                            }
                        else return 0;
        }
        i++;
    }
    return empty(s);
}
int main()
{
    char c[Max];
    printf("请输入一个想要检验的表达式（以#结尾）:\n");
    gets(c);
    puts(c);
    int a=parenthesis_matching(c);
    if(a)
    {
        printf("匹配！\n");
    }
    else
    printf("不匹配！\n");
    return 0;
}