c - 我正在尝试对单个链表进行排序

Question

我的代码运行错误!输入并排序列表中的某些数字后，对于某些数字，它不起作用并删除旧节点或不显示它们。无法弄清楚出了什么问题。

有时看起来工作正常，例如:我输入 4, 6, 7, 2，它确实显示在排序列表中。但输入3后列表中并没有显示3。

这是我的代码:

if(head == NULL)     
{
    head = info;    
    last = info;
    info->next = NULL;   
}
else  
{
    if(info->number > last->number)  
    {
        last->next = info;  
        last = info;            
        info->next = NULL;  
    }
    else if (info->number < head->number ) 
    {          
        info -> next = head;       
        head = info;            
    }

    prev = head;

    for(temp = head-> next ; temp!= NULL; temp = temp->next) 
    {
        prev = prev->next;
        if(info->number >temp->number)
        {
            temp->next = info;                          
        }
        else
        {
            temp-> prev = info;
            info = prev;
        }
    }
}   

Answer 1

if(head == NULL)     
{
    head = info;    
    last = info;

    info->next = NULL;   
}
else  
{
    if(info->number >= last->number)  <-- CHANGE:: > changed to >= to take care of same number (as earlier stored number) being entered
    {
        last->next = info;  
        last = info;            
        info->next = NULL;
        return;  <-- CHANGE:return added here, no need to proceed further
    }
    else if (info->number <= head->number) <-- CHANGE:: < changed to <= to take care of same number (as earlier stored number) being entered
    {         
        info -> next = head;       
        head = info;
        return; <-- CHANGE:return added here, no need to proceed further
    }

    prev = head;

    for(temp = head->next ; temp != NULL; temp = temp->next) 
    {
        if(temp->number >= info->number)  <-- CHANGE: modified code when insertion happens between head and last
        {
            prev->next = info;
            info->next = temp;
            break;
        }

        prev = temp;
    }
}  

在您的原始代码中，最后的 else 情况:

 else
 {
    temp-> prev = info;
    info = prev;
 }

由于您提到了单链表，因此这段代码没有任何意义，但在这里您使用了“temp->prev”。

当然，您的代码中还有减少代码大小的空间(可以删除 if 和 else-if 检查并直接执行“for”循环来插入新元素)