关于链表的基础有关问题
关于链表的基础问题
struct Link *AppendNode(struct Link *head, int newData);
void DispLink(struct Link *head);
void DelMemory(struct Link *head);
struct Link *DelNode(struct Link *head, int delData);
struct Link
{
int data;
struct Link *next;
};
void main()
{
struct Link *head = NULL;
int newData;
int delData;
char c;
printf("Append a new node.'Y' or 'y'\n");
scanf("%c", &c);
while(c == 'Y' || c == 'y')
{
printf("Input the data of new node:");
scanf("%d", &newData);
head = AppendNode(head, newData);
printf("Continue?");
scanf(" %c", &c);
}
DispLink(head);
printf("Delete a node:");
scanf("%d", &delData);
DelNode(head, delData);
DispLink(head);
DelMemory(head);
}
struct Link *AppendNode(struct Link *head, int newData) //动态链表的建立
{
struct Link *pr = head;
struct Link *newNode = NULL;
newNode = (struct Link *)malloc(sizeof(struct Link));
if(newNode == NULL) //检验是否有足够内存
{
printf("Not enough memory!\n");
exit(0);
}
if(head == NULL) //若为空链表,则新节点就是起始节点,也是结束节点
{ head = newNode; }
else //若不为空指针,则新节点添加到链表尾部
{
while(pr->next != NULL)
{ pr = pr->next; }
pr->next = newNode;
}
newNode->data = newData;
newNode->next = NULL;
return head;
}
void DispLink(struct Link *head) //显示节点数据
{
struct Link *pr = head;
int i = 1;
while(pr != NULL) //逐一打印节点数据
{
printf("%d, %d\n", i, pr->data);
pr = pr->next;
i++;
}
}
void DelMemory(struct Link *head) //释放节点内存
{
struct Link *pr = head, *del = NULL;
while(pr != NULL) //逐一释放节点
{
del = pr;
pr = pr->next;
free(del);
}
}
struct Link *DelNode(struct Link *head, int delData) //链表的删除操作
{
struct Link *pr = head, *del = NULL;
if(head == NULL) //若为空链表,无需删除
{
printf("Link does not exist!");
return head;
}
while((pr->data != delData) && (pr->next != NULL))
{
pr = pr->next;
}
if(pr->data == delData) //若找到要删除的节点,则释放该节点
{
del = pr;
pr = pr->next;
free(del);
}
else
{ printf("Not Found!\n"); } //若没有找到,则返回“未找到”
return head;
}
整个代码的目的是创建节点,删除节点。
大概是:1.创建节点。2.打印创建结果。3.删除某个节点。4.再打印删除后的结果。在4的打印结果来看,是没有实现3的功能,麻烦大家指出错误。
------解决方案--------------------
struct Link *AppendNode(struct Link *head, int newData);
void DispLink(struct Link *head);
void DelMemory(struct Link *head);
struct Link *DelNode(struct Link *head, int delData);
struct Link
{
int data;
struct Link *next;
};
void main()
{
struct Link *head = NULL;
int newData;
int delData;
char c;
printf("Append a new node.'Y' or 'y'\n");
scanf("%c", &c);
while(c == 'Y' || c == 'y')
{
printf("Input the data of new node:");
scanf("%d", &newData);
head = AppendNode(head, newData);
printf("Continue?");
scanf(" %c", &c);
}
DispLink(head);
printf("Delete a node:");
scanf("%d", &delData);
DelNode(head, delData);
DispLink(head);
DelMemory(head);
}
struct Link *AppendNode(struct Link *head, int newData) //动态链表的建立
{
struct Link *pr = head;
struct Link *newNode = NULL;
newNode = (struct Link *)malloc(sizeof(struct Link));
if(newNode == NULL) //检验是否有足够内存
{
printf("Not enough memory!\n");
exit(0);
}
if(head == NULL) //若为空链表,则新节点就是起始节点,也是结束节点
{ head = newNode; }
else //若不为空指针,则新节点添加到链表尾部
{
while(pr->next != NULL)
{ pr = pr->next; }
pr->next = newNode;
}
newNode->data = newData;
newNode->next = NULL;
return head;
}
void DispLink(struct Link *head) //显示节点数据
{
struct Link *pr = head;
int i = 1;
while(pr != NULL) //逐一打印节点数据
{
printf("%d, %d\n", i, pr->data);
pr = pr->next;
i++;
}
}
void DelMemory(struct Link *head) //释放节点内存
{
struct Link *pr = head, *del = NULL;
while(pr != NULL) //逐一释放节点
{
del = pr;
pr = pr->next;
free(del);
}
}
struct Link *DelNode(struct Link *head, int delData) //链表的删除操作
{
struct Link *pr = head, *del = NULL;
if(head == NULL) //若为空链表,无需删除
{
printf("Link does not exist!");
return head;
}
while((pr->data != delData) && (pr->next != NULL))
{
pr = pr->next;
}
if(pr->data == delData) //若找到要删除的节点,则释放该节点
{
del = pr;
pr = pr->next;
free(del);
}
else
{ printf("Not Found!\n"); } //若没有找到,则返回“未找到”
return head;
}
整个代码的目的是创建节点,删除节点。
大概是:1.创建节点。2.打印创建结果。3.删除某个节点。4.再打印删除后的结果。在4的打印结果来看,是没有实现3的功能,麻烦大家指出错误。
------解决方案--------------------
- C/C++ code
struct Link *DelNode(struct Link *head, int delData) //链表的删除操作 { struct Link *pr = head, *del = NULL; if(head == NULL) //若为空链表,无需删除 { printf("Link does not exist!"); return head; } while((pr->data != delData) && (pr->next != NULL)) { del = pr; pr = pr->next; } if(pr->data == delData) //若找到要删除的节点,则释放该节点 { del->next = pr->next; free(pr); } else { printf("Not Found!\n"); } //若没有找到,则返回“未找到” return head; }
------解决方案--------------------
链表←指针←内存地址
VC调试(TC或BC用TD调试)时按Alt+8、Alt+6和Alt+5,打开汇编窗口、内存窗口和寄存器窗口看每句C对应的汇编、单步执行并观察相应内存和寄存器变化,这样过一遍不就啥都明白了吗。
对VC来说,所谓‘调试时’就是编译连接通过以后,按F10或F11键单步执行一步以后的时候,或者在某行按F9设了断点后按F5执行停在该断点处的时候。
(Linux或Unix下可以在用GDB调试时,看每句C对应的汇编并单步执行观察相应内存和寄存器变化。)
想要从本质上理解C指针,必须学习汇编以及C和汇编的对应关系。
从汇编的角度理解和学习C语言的指针,原本看似复杂的东西就会变得非常简单!
指针即地址。“地址又是啥?”“只能从汇编语言和计算机组成原理的角度去解释了。”
这辈子不看内存地址和内存值;只画链表、指针示意图,画堆栈示意图,画各种示意图,甚至自己没画过而只看过书上的图……能从本质上理解指针、理解函数参数传递吗?本人深表怀疑!