Question

数据结构链式存储队列中删除元素的算法

如题，链式存储队列中删除元素的算法？希望高手指点，谢谢了！

Answer 1

给你一个全的吧
#include<iostream>
#include<stdlib.h>
using namespace std;
typedef struct LNode
{
int Data;
struct LNode *Next;
}LNode;

void CreateList(struct LNode *HeadList,int n,int a[])
{
int i;
struct LNode *p;
HeadList=(struct LNode*)malloc(sizeof(struct LNode));
HeadList->Next=NULL;
for(i=n;i>0;--i)
{
p=(struct LNode*)malloc(sizeof(struct LNode));
p->Data=a[i];
p->Next=HeadList->Next;
HeadList->Next=p;
}
}
void ListInsert(struct LNode *HeadList,int i,int newnode)
{
struct LNode *p=HeadList;
struct LNode *s;
int j=0;
while(p && j<i-1)
{
p=p->Next;
j++;
}
if(!p || j>i-1)
{
cout<<"位置小于1或大于表长";
return;
}
s=(struct LNode*)malloc(sizeof(struct LNode));
s->Data=newnode;
s->Next=p->Next;
p->Next=s;
}
void ListDelete(struct LNode *HeadList,int i)
{
struct LNode *p=HeadList;
struct LNode *s;
int j=0;
while(p->Next && j<i-1)
{
p=p->Next;
++j;
}
if(!(p->Next) || j>i-1)
{
cout<<"删除位置不合理";
return;
}
s=p->Next;
p->Next=s->Next;
int number;
cin>>number;
s->Data=number;
cout<<"被删除的结点是"<<s->Data;
free(s);
}
void ListDisp(struct LNode *HeadList)
{
struct LNode *p;
int i=0;
p=HeadList->Next;
while(p)
{
cout<<p->Data;
++i;
p=p->Next;
}
}
int getoptions()
{
int opt;
cout<<"1: 录入链表"<<endl;
cout<<"2: 显示链表"<<endl;
cout<<"3: 插入结点"<<endl;
cout<<"4: 删除结点"<<endl;
cout<<"5: 退出"<<endl;
cout<<"输入选项并按回车确认:";
cin>>opt;
return opt;
}
int main(int argc,char * argv[])
{
int opt;
int where;
int value;
int count;
int a[5]={2,4,6,8,10};
struct LNode *HeadList;
while(1)
{
opt=getoptions();
if(opt==1)
{
//cout<<"请输入链表的初始结点数";
//cin>>count;
//cout<<"请输入各个结点数值，每输入一个按回车确认";
CreateList(HeadList,5,a);
ListDisp(HeadList);
system("PAUSE");
continue;
}
if(opt==2)
{
ListDisp(HeadList);
system("PAUSE");
continue;
}
if(opt==3)
{
ListDisp(HeadList);
cin>>where;
cout<<"请输入要插入的数值";
cin>>value;
ListInsert(HeadList,where,value);
ListDisp(HeadList);
system("PAUSE");
continue;
}
if(opt==4)
{
ListDisp(HeadList);
cout<<"请输入要删除的位置";
cin>>where;
ListDelete(HeadList,where);
ListDisp(HeadList);
system("PAUSE");
continue;
}
if(opt==5)
{
return 0;
}
}
}
不好意思，我发完之后才看见是队列，乍一看以为是链表，我发的这个是链表的，快下班了，明天上班再给你写一个吧

Answer 2

typedef char ElemType;
typedef struct QNode{
ElemType data;
struct QNode *next;
} QNode , *QueuePtr;
typedef struct{
QueuePtr front; //队头指针
QueuePtr rear; //队尾指针
}LinkQueue;

void DeQueue(LinkQueue *q, ElemType *e){
/*如果队列q不为空，删除q的队头元素，用e返回其值*/
QueuePtr p;
if(q->front == q->rear) return; /*队列为空，返回*/
p = q->front->next;
*e = p->data;
q->front->next = p->next;
if(q->rear == p) q->rear = q->front; /*如果队头就是队尾，则修改队尾指针*/
free(p);
}