数据结构双链表实现代码.doc

数据结构双链表实现函数#include #include /*双向链表的定义*/struct llist struct llist *prior; int num; struct llist *next; ;typedef struct llist node; typedef node *llink; /*双向链表的输出*/void printllist(llink head) llink ptr; ptr = head-next; while ( ptr != NULL ) printf(%d,ptr-num); ptr = ptr-next; printf(n); /*双向链表的倒序输出*/void printllist2(llink head) llink ptr; ptr = head; while( ptr-next != NULL )ptr=ptr-next; while ( ptr != head ) printf(%d,ptr-num); ptr = ptr-prior; printf(n); /*双向链表的创建*/llink createllist(int *array,int len) llink head; /* 双向链表的开始指针 */ llink ptr,ptr1; int i; /* 建立开头结点 */ head = ( llink ) malloc(sizeof(node); /* 分配内存 */ if ( !head ) /* 检查指针 */ return NULL; ptr = head;/* 将ptr指向链表开始 */ for ( i = 0; i num = arrayi; /* 建立结点内容 */ ptr1-next = NULL; /* 设定指针初值 */ ptr1-prior = NULL; ptr-next = ptr1; /* 连接结点 */ ptr1-prior = ptr; ptr = ptr-next; return head;/*双向链表的结点插入*/llink insertnode(llink head,llink ptr,int value) llink new1,ptr1=head; /* 新结点指针变量 */ while(ptr1!=ptr)ptr1=ptr1-next; if(!ptr1) printf(找不到插入位置，插入位置有误n); return head; new1= ( llink ) malloc(sizeof(node); if ( !new1 ) return NULL; new1-num = value; /* 设定初值 */ new1-next = NULL; new1-prior = NULL; new1-next = ptr-next;/* 交换4个指针*/ ptr-next-prior = new1; ptr-next = new1; new1-prior = ptr; return head;/* 返回头结点 */*双向链表的结点删除*/llink deletenode(llink head,llink ptr)if(!(head-next) /* 链表为空直接返回头指针 */printf(删除链表为空n);return head; llink previous; previous = head;if(ptr) while ( previous-next != ptr ) /* 找结点ptr前一结点 */ previous = previous-next;/* 找结点ptr前一结点之后进行删除操作 */previous-next = ptr-next; ptr-next-prior=previous; /* 删除中间结点 */elsewhile ( previous-next-next != NULL )previous = previous-next;ptr= previous-next;previous-next = ptr-next;free(ptr); return head;/* 返回头结点 */*主程序*/void main()int llist16 = 1, 2, 3, 4, 5, 6 ; llink head; /* 建立链表并输出*/ head = createllist(llist1,6); if ( !head ) printf(内存分配失败! n); exit(1); printf(原来的链表: ); printllist(head); /* 插入新结点(在表头插入元素0)*/ head = insertnode(head,head,0); if ( !head ) printf(内存分配失败! n); exit(1); printf(插入结点后的链表: ); printllist(head); /* 删除链内结点(删除第三个结点) */ head = deletenode(head,head-nex