谁能解释一下这段C语言

typedef struct{
StElem *base;
StElem *top;
int stacksize;
} SqStack;

typedef struct{
int front;
int rear;
QuElem *base;
} SqQueue;

typedef int status;

status InitStack(SqStack *s)
{
s->base=(StElem *)malloc(GARAGESIZE*sizeof(StElem));
if(!s->base) exit(OVERFLOW);
s->top=s->base;
s->stacksize=GARAGESIZE;
return OK;
}

status Push(SqStack *s,StElem e)
{
if(s->top-s->base==s->stacksize) return ERROR;
*s->top++=e;
return OK;
}

status Pop(SqStack *s,StElem *e)
{
if(s->top==s->base) return ERROR;