#include #includetypedefintElemType;
typedefstructDLNode{
ElemType data;struct DLNode *next;struct DLNode *prior;
}DLNode;
DLNode*InitList(DLNode *DL);//初始化
int ListEmpty(DLNode *DL);//判空
int ListLength(DLNode *DL);//返回链表长度
int ListInsert(DLNode *DL, int i, ElemType e);//插入元素
int ListDelete(DLNode *DL, int i);//删除第i个元素
void TraverseList(DLNode *DL);//遍历线性表//初始化
DLNode* InitList(DLNode *DL){intx;
DLNode*p =NULL;
DLNode*r =NULL;
DL= (DLNode *)malloc(sizeof(DLNode));
DL->next =DL;
DL->prior =DL;
r=DL;
printf("输入直到-1为止\n");while(1){
scanf("%d", &x);if(x == -1){
printf("初始化成功\n");break;
}
p= (DLNode *)malloc(sizeof(DLNode));if(p){
p->data =x;
p->prior =r;
p->next =DL;
r->next =p;
DL->prior =p;
r=p;
}else{
printf("空间不足初始化失败\n");returnNULL;
}
}returnDL;
}//判空
int ListEmpty(DLNode *DL){return (DL->next ==DL);
}//插入元素
int ListInsert(DLNode *DL, inti, ElemType e){if(i>ListLength(DL)+1 || i<=0){
printf("插入位置有误，插入失败\n");return 0;
}
DLNode*p =DL;int j = 0;while(j
p= p->next;
j++;
}
DLNode*nDLNode = (DLNode *)malloc(sizeof(DLNode));
nDLNode->data =e;
nDLNode->prior = p->prior;
p->prior->next =nDLNode;
p->prior =nDLNode;
nDLNode->next =p;
printf("插入成功\n");return 1;
}//删除第i个元素
int ListDelete(DLNode *DL, inti){if(i>ListLength(DL) || i<=0){
printf("删除位置有误，插入失败\n");return 0;
}
DLNode*p =DL;int j = 0;while(j
p= p->next;
j++;
}
p->prior->next = p->next;
p->next->prior = p->prior;free(p);
printf("删除成功\n");return 1;
}//返回链表长度
int ListLength(DLNode *DL){int len = 0;if(ListEmpty(DL)) return 0;
DLNode*p = DL->next;while(p->data!=DL->data){
len++;
p= p->next;
}returnlen;
}//遍历线性表
void TraverseList(DLNode *DL){if(ListEmpty(DL)){
printf("空链表");
}
DLNode*p = DL->next;//终止循环遍历
while(p->data != DL->data){
printf("%d", p->data);
p= p->next;
}
printf("\n");
}intmain(){
ElemType e=NULL;
DLNode*DL =NULL;//初始化测试
DL =InitList(DL);// //等价测试//DLNode *d = DL->next->next;//if(d->next->prior == d->prior->next){//printf("d->next->prior == d->prior->next\n");//}//if(d->next->prior == d){//printf("d->next->prior == d\n");//}//if(d == d->prior->next){//printf("d == d->prior->next\n");//}//遍历测试
TraverseList(DL);//
//printf("双向循环链表长度为%d\n",ListLength(DL));//插入元素测试
printf("第3个位置插入999\n");
ListInsert(DL,3, 999);
TraverseList(DL);//-----------------------------------------------------//非法操作?循环双向链表插入一个巨大的位置是否合法？//和老师讨论完，算不合法
printf("第567位置插入999\n");
ListInsert(DL,567, 999);
TraverseList(DL);//------------------------------------------------------//删除元素测试//printf("删除第1个位置\n");//ListDelete(DL, 1);//TraverseList(DL);//------------------------------------------------------//非法操作?同上//新问题，1，2，3，4，-1，删除第5个是头节点。//和老师讨论完，算不合法//printf("删除第55位置\n");//ListDelete(DL, 55);//TraverseList(DL);//------------------------------------------------------
}
