1 #include
       
         2 #include
        
          3 #include
         
           4 typedef char elemtype; 5 typedef struct node 6 { 7     char data; 8     struct node *next; 9 }stack;10 stack *top;11 void push(elemtype n)//进栈12 {13     stack *p;14     p=(stack *)malloc(sizeof(stack));15     p->data=n;16     p->next=top->next;17     top->next=p;18 }19 void pop()//出栈20 {21     stack *q;22     q=top->next;23     top->next=q->next;24     free(q);//释放内存25 }26 char gettop()//取栈顶元素27 {28     return top->next->data;29 }30 void judge(char a[])31 {32     int i,tag=0,len=strlen(a);33     for(i=0;i
          
           next==NULL)//有了右半个括号，但是没有左半个括号的情况43         {44             printf("no\n");45             break;46         }47         if(a[i]-gettop()==1||a[i]-gettop()==2)//判断是否匹配48             pop();  //出栈49         else50         {51             printf("no\n");52             break;53         }54     }55     if(i==len)//如果没有遍历到头，此语句不执行56     {57         if(top->next==NULL)58         printf("yes\n");59         else printf("no\n");60     }61     top->next=NULL;//置栈空62 }63 int main()64 {65     top=(stack *)malloc(sizeof(stack));//申请头节点空间66     top->next=NULL;//头节点指向空67     char a[100];68     while(gets(a)!=NULL)69     {70         judge(a);71     }72     return 0;73 }
          
         
        
       

1 #include 
       
         2 #include 
        
          3 #include 
         
           4 #define MAXN 200 5 int st[MAXN]; 6 int main(){ 7     int top, i, len, flag; 8     char s[100]; 9     while(gets(s)){10         len = strlen(s);11         top = 0; flag = 1;12         for(i=0; i