#include <stdio.h>
#include <string.h>
#include <stdlib.h>
/** function:* 创建一个双向链表，将26个英文字母通过头插的方式插入，通过为尾删的方式读取并删除* @param [ in] * @param [out] * @return      */
typedef struct double_link_list{char data;struct double_link_list * pre;struct double_link_list * next;
}node,*pnode;
pnode listInit(){pnode H=(pnode)malloc(sizeof(node));if(NULL==H){printf("__%d__malloc failed",__LINE__);}H->data=0;H->pre=NULL;H->next=NULL;return H;
}
int headInsert(pnode H,char data){if(H==NULL){puts("null pont pass");return -1;}pnode newNode=(pnode)malloc(sizeof(node));newNode->data=data;newNode->next=H->next;if(H->next!=NULL)H->next->pre=newNode;H->next=newNode;newNode->pre=H;printf("%c insert success\n",H->next->data);return 0;
}
int tailDelete(pnode H){if(H==NULL){puts("null pont pass");return -1;}pnode p=H;//p指向最后一个节点while(p->next!=NULL){p=p->next;}while(p->pre!=NULL){printf("%c->",p->data);pnode del=p;p=p->pre;free(del);}return 0;
}
int print(pnode H){if(H==NULL){puts("null pont pass");return -1;}pnode p=H;//p指向最后一个节点while(p->next!=NULL){printf("%c->",p->next->data);p=p->next;}printf("last=%c\n",p->data);return 0;
}
int main(int argc, const char *argv[])
{pnode H=listInit();for (char i='a'; i<='z'; i++){headInsert(H,i);}tailDelete(H);//print(H);return 0;
}

运行结果：