栈的表示与实现

顺序栈

typedef struct
{
    int elem[MAXN];
    int top;
}SeqStack;
void InitStack(SeqStack *S)
{
    S->top=-1;
}
void Push(SeqStack *S ,int x)   //栈的首元素下标是0
{
    if(S->top==MAXN-1) //栈已满
    return;
    S->top++;
    S->elem[S->top]=x;
    return;
}
void Pop(SeqStack *S )
{
   if(S->top==-1)    //栈为空
   return;
   else
   {
       S->top--;
       return;
   }
}
int GetTop(SeqStack *S )
{
    int x;
    if(S->top==-1)  //栈为空
    return -10000;
    else
    {
        x=S->elem[S->top];
    }
    return x;
}