#include <iostream>
using namespace std;
typedef int ElemType;typedef struct DuLNode {//节点的创建ElemType data;struct DuLNode *prior, *next;
} DuLNode, *DuLinkList;bool InitList(DuLinkList &L) {//初始化L = new DuLNode;if (L == NULL) {cout << "开辟空间失败" << endl;return false;}L->next = L;L->prior = L;return true;
}DuLNode *GetElemp_DuL(DuLinkList L, int i) {//得到指向i位置的指针DuLNode *p;p = L;int j = 0;while (j < i && p) {j++;p = p->next;}if ( j > i || !p)return NULL;return p;
}bool ListInsert(DuLinkList &L, int i, ElemType e) {//在i前面插入元素eDuLNode *p;if (!(p = GetElemp_DuL(L, i)))return false;DuLNode *s;s = new DuLNode;s->prior = p->prior;p->prior->next = s;s->next = p;p->prior = s;return true;
}bool ListDelete(DuLinkList &L, int i, ElemType &e) {//删除i位置的元素DuLNode *p;if (!(p = GetElemp_DuL(L, i)))return false;e = p->data;p->prior->next = p->next;p->next->prior = p->prior;free(p);return true;
}