删除表中第i个元素
- 头结点及尾结点指针域的变化
- 查找过程中循环条件的变化
- 删除元素过程中的指针运算
如图：
程序；
#include<stdio.h>
#include<stdlib.h>
#define OK 1
#define ERROR 0
#define OVERFLOW 0
typedef struct DuLNode{
int data;
struct DuLNode *prior;
struct DuLNode *next;
}DuLNode,*DuLinkList;
//建立一个只含头结点的空双向循环链表
int InitList_DuL(DuLinkList &L){
L=(DuLinkList)malloc(sizeof(DuLNode));
if(!L){
exit(OVERFLOW);
}
L->prior=L;
L->next=L;
return OK;
}
int CreateList_DuL(DuLinkList &L,int n){
DuLinkList p,q;
int i;
printf("Input the datas:");
q=L;
for(i=0;i<n;i++){
p=(DuLinkList)malloc(sizeof(DuLNode));
scanf("%d",&p->data);
p->next=q->next;
// p->next=L->next;
q->next=p;
p->prior=q;
L->prior=p;
q=p;
}
return OK;
}
int ListDelete_DuL(DuLinkList &L,int i,int &e){ //删除表中第i个元素，由变量e返回其值
DuLinkList p;
int j=1;
p=L->next;
while(p!=L&&j<i){
p=p->next;//查找第i个节点
++j;
}
while(p==L||j>i){
return ERROR;
}
e=p->data;
p->prior->next=p->next;
p->next->prior=p->prior;
free(p);
return OK;
}
int TraverseList_DuL(DuLinkList L){//遍历
DuLinkList p;
p=L->next;
while(p!=L){
printf("%d",p->data);
p=p->next;
}
return OK;
}
main(){
int i,n,e;
DuLinkList L;
InitList_DuL(L);
printf("Input the length of the list L:");
scanf("%d",&n);
CreateList_DuL(L,n);
printf("Input the delete location:");
scanf("%d",&i);
if(ListDelete_DuL(L,i,e)){
printf("Output the datas:");
TraverseList_DuL(L);
}else{
printf("Can't delete the data!");
}
printf("
");
}
结果：
android@android-Latitude-E4300:~/work/c/doublelianbiao$ ./listdelete
Input the length of the list L:5
Input the datas:1 3 5 7 9
Input the delete location:2
Output the datas:1579