指针空间分配问题？debug出错了

Question

---

typedef string ElemType;

typedef struct LNode {

ElemType data;

struct LNode next;

}LNode,*LinkList;

Status ListInit(LinkList &l) {

l = (LinkList)malloc(sizeof(LNode));

l->next = NULL;

l->data = "";

return OK;
}
void main(){
LinkList l;
ListInit(l);
}
编译没错
debug时
Unhandled exception at 0x01232df6 in TEST.exe: 0xC0000005: Access violation writing location 0xcdcdc
但换成typedef int ElemType;就没报错了***