蔡子经数据结构1.8

#define MAXN 100

int stack[MAXN];
int topl = 0;
int topr = MAXN-1;

void (int n, int x)
{
    if(topr < topl)
    {
        puts("overflowed");
        return ;
    }
    if(n == 1)
    {
        stack[topl++] = x;
    }
    else//右边入栈
    {
        stack[topr--] = x;
    }
}

int pop(int n)
{
    if(n == 1)//左边出栈
    {
        if(topl == 0)
        {
            puts("empty");
            return -1;
        }
        return stack[--topl];
    }
    else//右边
    {
        if(topr == MAXN-1)
        {
            puts("empty");
            return -1;
        }
        return stack[++topr];
    }
}

int main()
{
    int n,x;
    while(scanf("%d",&n) != EOF)
    {
        if(n == 1)//表示入栈
        {
            scanf("%d %d",&n,&x);
            push(n, x);
        }
        else//否则就是出栈
        {
            scanf("%d",&n);
            printf("%dn",pop(n));
        }
    }
    return 0;
}