C语言，双向循环链表

Question

输入格式:
输入一个字符串，长度不超过5×104，包含大小写字母、空格、下划线、{、}、<、>、#，表示贝蒂和哈利的按键序列。
输出格式:
输出为屏幕上最终显示的字符串。
输入样例1:
jlu_cc{i_love_}st
输出样例1:
i_love_jlu_ccst

Answer 1

#include<stdio.h>
#include<stdlib.h>
struct Queue{
    char data;
    struct Queue *last,*next;
}head,tail,*now;

void input(char ch);
void deleteNode();
int main()
{
    head.next = &tail;
    tail.last = &head;
    tail.data = '\0';
    now = &head;

    char s[100001];
    gets(s);
    for(int z=0;s[z]!='\0';z++){
        if(s[z]=='{') now = &head;
        if(s[z]=='}') now = tail.last;
        if(s[z]=='<' && now!=&head) now = now->last;
        if(s[z]=='>' && now!=tail.last) now = now->next;
        if(s[z]=='#') deleteNode();
        input(s[z]);
    }

    head = *head.next;
    while (head.data!='\0'){
        putchar(head.data);
        head = *head.next;
    }

    return 0;
}
void input(char ch){
    if(ch=='{' || ch=='}' || ch=='<' || ch=='>' || ch=='#') return;
    struct Queue *node;
    node = (Queue *)malloc(sizeof(struct Queue));
    node->data = ch;
    node->next = now->next;
    now->next->last = node;
    node->last = now;
    now->next = node;
    now = now->next;
}
void deleteNode(){
    if(now==&head) return;
    struct Queue *flag = now;
    now = now->last;
    now->next = flag->next;
    flag->next->last = now;
    free(flag);
}

#include<stdio.h>
#include<stdlib.h>
struct Queue{
    char data;
    struct Queue *last,*next;
}head,tail,*now;

void input(char ch);
void deleteNode();
int main()
{
    head.next = &tail;
    tail.last = &head;
    tail.data = '\0';
    now = &head;

    char s;


    while (scanf("%c",&s) && s!='\n'){
        if(s=='{') now = &head;
        if(s=='}') now = tail.last;
        if(s=='<' && now!=&head) now = now->last;
        if(s=='>' && now!=tail.last) now = now->next;
        if(s=='#') deleteNode();
        input(s);
    }

    head = *head.next;
    while (head.data!='\0'){
        putchar(head.data);
        head = *head.next;
    }

    return 0;
}
void input(char ch){
    if(ch=='{' || ch=='}' || ch=='<' || ch=='>' || ch=='#') return;
    struct Queue *node;
    node = (struct Queue *)malloc(sizeof(struct Queue));
    node->data = ch;
    node->next = now->next;
    now->next->last = node;
    node->last = now;
    now->next = node;
    now = now->next;
}
void deleteNode(){
    if(now==&head) return;
    struct Queue *flag = now;
    now = now->last;
    now->next = flag->next;
    flag->next->last = now;
    free(flag);
}