C 打印双链表
我有一个家庭作业要写“先到先得”和“循环模拟”并比较它们。我开始创建一个链表来制作事件列表。我制作了插入和打印列表函数,但无法使其工作。我的朋友告诉我使用双链表,所以我重新创建了链表,并试图使打印功能正常工作。我有一个关于插入函数的问题,因为我在while循环中的语句顺序有错误。在修复了许多错误后,print函数会多次打印同一个节点,而不是整个列表。我不知道程序的哪一部分是错的。我认为我在insert函数中有错误,我把指针指向了错误的地方,所以我把事件指向了它自己,或者我在print函数中有错误 当我删除这行代码时,打印功能只打印当前节点,而不打印其他节点 新建指针->下一步=*事件列表 我想这意味着我在这部分有问题,但我不明白为什么C 打印双链表,c,doubly-linked-list,C,Doubly Linked List,我有一个家庭作业要写“先到先得”和“循环模拟”并比较它们。我开始创建一个链表来制作事件列表。我制作了插入和打印列表函数,但无法使其工作。我的朋友告诉我使用双链表,所以我重新创建了链表,并试图使打印功能正常工作。我有一个关于插入函数的问题,因为我在while循环中的语句顺序有错误。在修复了许多错误后,print函数会多次打印同一个节点,而不是整个列表。我不知道程序的哪一部分是错的。我认为我在insert函数中有错误,我把指针指向了错误的地方,所以我把事件指向了它自己,或者我在print函数中有错误
if(prevptr == NULL) //if putting node at the beginning of the list
{
printf("DONEW\n");
newpointer->next = *eventlist;
*eventlist = newpointer;
}
你能告诉我密码有什么问题吗
#include <stdio.h>
#include <stdlib.h>
struct event {
struct event *next;
int processid;
int arrivaltime;
int cputime;
};
typedef struct event Event;
typedef Event *eventPtr;
Event create_node(int processid, int arrivaltime, int cputime);
void add_event(Event *newpointer, eventPtr *eventlist);
void print_node(Event node);
void print_eventlist(Event *eventlist);
Event get_nextevent(Event *eventlist);
int main(int argc, char* argv[])
{
int sourcenum,a,b,c,i;
Event tempevent;
eventPtr eventlist = NULL;
print_eventlist(eventlist);
char* sources,timeSlice;
if(argc != 3)
printf("Proper usage is: main.c sources time-slice\n");
else
{
sourcenum = atoi(argv[1]);
timeSlice = atoi(argv[2]);
for(i = 0; i < sourcenum ; i++)
{
//print_eventlist(&(*eventlist));
printf("please enter the process-id, arrival-time and cpu-time.\n");
scanf("%d %d %d",&a, &b, &c);
printf("something\n");
tempevent = create_node(a,b,c);
printf("something\n");
add_event(&tempevent, &eventlist);
print_eventlist(eventlist);
}
print_eventlist(eventlist);
}
return 0;
}
void add_event(Event *newpointer, eventPtr *eventlist) //insert
{
printf("DONE1\n");
eventPtr currentptr, prevptr;
printf("DONE2\n");
prevptr = NULL;
printf("DONE3\n");
currentptr = *eventlist;
printf("DONE4\n");
while((currentptr != NULL && currentptr->arrivaltime < newpointer->arrivaltime)) /*on every loop previous and current pointer gets upgraded*/
{
printf("DONEW\n");
prevptr = currentptr;
currentptr = currentptr->next;
}
printf("DONEW\n");
if(prevptr == NULL) //if putting node at the beginning of the list
{
printf("DONEW\n");
newpointer->next = *eventlist;
*eventlist = newpointer;
}
else //putting list between current and previous
{
printf("DONEW\n");
prevptr->next = newpointer;
newpointer->next = currentptr;
}
printf("DONE\n");
}
Event create_node(int processid, int arrivaltime, int cputime)
{
Event *ptr;
ptr = malloc(sizeof(Event));
if(ptr != NULL)
{
ptr->processid = processid;
ptr->arrivaltime = arrivaltime;
ptr->cputime = cputime;
ptr->next = NULL;
}
return *ptr;
}
void print_node(Event node)
{
printf("process-id = %d\n",node.processid);
printf("Arrival Time = %d\n",node.arrivaltime);
printf("CPU time = %d\n",node.cputime);
}
void print_eventlist(eventPtr currentPtr) /*function receives an eventlist and prints all of the events*/
{
if(currentPtr == NULL)
{
puts("List is empty\n");
}
else
{
puts("The List is:");
while(currentPtr != NULL)
{
printf("==========================================\n");//list #%d\n",i);
print_node(*currentPtr);
printf("\n==========================================\n");
currentPtr = currentPtr->next;
}
puts("NULL\n");
}
}
/*int i=0; //This is what I had before
eventPtr currentptr;
*currentptr = *eventlist;
printf("something!!!");
while(currentptr != NULL)
{
i++;
printf("==========================================\nlist #%d\n",i);
print_node(*currentptr);
printf("\n==========================================\n");
currentptr = currentptr->next;
}
}*/
/*Event get_nextevent(Event *eventlist)
{
Event newstruct = create_node(eventlist->processid, eventlist->arrivaltime, eventlist->cputime);
eventlist = eventlist->next;
return newstruct;
}*/
#包括
#包括
结构事件{
结构事件*下一步;
int进程ID;
到达时间;
int cputime;
};
typedef结构事件;
typedef事件*eventPtr;
事件创建_节点(int processid、int arrivaltime、int cputime);
void add_事件(event*newpointer,eventPtr*eventlist);
作废打印节点(事件节点);
作废打印事件列表(事件*事件列表);
事件获取下一个事件(事件*事件列表);
int main(int argc,char*argv[])
{
int sourcenum,a,b,c,i;
事件-事件;
eventPtr eventlist=NULL;
打印事件列表(eventlist);
字符*源,时间片;
如果(argc!=3)
printf(“正确用法是:main.c源时间片\n”);
其他的
{
sourcenum=atoi(argv[1]);
时间片=atoi(argv[2]);
对于(i=0;iarrivaltimearrivaltime))/*在每个循环上,上一个和当前指针都得到升级*/
{
printf(“DONEW\n”);
prevptr=当前Ptr;
currentptr=currentptr->next;
}
printf(“DONEW\n”);
if(prevptr==NULL)//如果将节点放在列表的开头
{
printf(“DONEW\n”);
新建指针->下一步=*事件列表;
*eventlist=newpointer;
}
else//将列表置于当前和上一个列表之间
{
printf(“DONEW\n”);
prevptr->next=newpointer;
newpointer->next=currentptr;
}
printf(“完成”\n);
}
事件创建_节点(int processid、int arrivaltime、int cputime)
{
事件*ptr;
ptr=malloc(sizeof(Event));
如果(ptr!=NULL)
{
ptr->processid=processid;
ptr->到达时间=到达时间;
ptr->cputime=cputime;
ptr->next=NULL;
}
返回*ptr;
}
无效打印节点(事件节点)
{
printf(“进程id=%d\n”,node.processid);
printf(“到达时间=%d\n”,node.arrivaltime);
printf(“CPU时间=%d\n”,node.cputime);
}
void print_eventlist(eventPtr currentpr)/*函数接收事件列表并打印所有事件*/
{
如果(currentPtr==NULL)
{
puts(“列表为空\n”);
}
其他的
{
puts(“列表为:”);
while(currentPtr!=NULL)
{
printf(“===========================================\n”);//列表#%d\n”,i);
打印节点(*currentPtr);
printf(“\n=======================================================\n”);
currentPtr=currentPtr->next;
}
放置(“空\n”);
}
}
/*int i=0;//这是我以前拥有的
事件ptr当前ptr;
*currentptr=*事件列表;
printf(“某物!!!”);
while(currentptr!=NULL)
{
i++;
printf(“====================================================\n列出%d\n”,i);
打印节点(*currentptr);
printf(“\n=======================================================\n”);
currentptr=currentptr->next;
}
}*/
/*事件获取下一个事件(事件*事件列表)
{
Event newstruct=create_节点(eventlist->processid,eventlist->arrivaltime,eventlist->cputime);
事件列表=事件列表->下一步;
返回newstruct;
}*/
更改以下类型:
Event tempevent;
到
您遇到的问题是传递&tempevent和Event tempevent时,此地址始终相同。请更改create_节点以返回eventPtr
eventPtr create_node(int processid, int arrivaltime, int cputime)
{
Event *ptr;
ptr = malloc(sizeof(Event));
if(ptr != NULL)
{
ptr->processid = processid;
ptr->arrivaltime = arrivaltime;
ptr->cputime = cputime;
ptr->next = NULL;
}
return ptr;
}
在这段代码中有很多东西需要解决 首先,您正在
create_node
中泄漏内存。该函数应设计为动态分配事件,使用传递的参数准备事件,并将其作为要分配给调用方端指针的地址返回给调用方:
Event* create_node(int processid, int arrivaltime, int cputime)
{
Event *ptr = malloc(sizeof(*ptr));
if (ptr == NULL)
{
perror("Failed to allocate Event.");
exit(EXIT_FAILURE);
}
ptr->processid = processid;
ptr->arrivaltime = arrivaltime;
ptr->cputime = cputime;
ptr->next = NULL;
return ptr;
}
接下来,您的add_event
函数应将事件指针作为列表头,理想情况下,该指针的地址应允许在初始插入时对其进行修改。插入函数有两种思路:(1)始终返回列表头,以及(2)使用指向列表头参数的指针,并根据需要通过取消引用对其进行修改。我更喜欢后者,
Event* create_node(int processid, int arrivaltime, int cputime)
{
Event *ptr = malloc(sizeof(*ptr));
if (ptr == NULL)
{
perror("Failed to allocate Event.");
exit(EXIT_FAILURE);
}
ptr->processid = processid;
ptr->arrivaltime = arrivaltime;
ptr->cputime = cputime;
ptr->next = NULL;
return ptr;
}
// link an event on to the end of our linked list.
void add_event(Event** pp, Event* event)
{
while (*pp)
pp = &(*pp)->next;
*pp = event;
}
#include <stdio.h>
#include <stdlib.h>
typedef struct event
{
struct event *next;
int processid;
int arrivaltime;
int cputime;
} Event;
Event* create_node(int processid, int arrivaltime, int cputime);
void add_event(Event** head, Event *event);
void print_node(const Event* node);
void print_eventlist(const Event *eventlist);
int main(int argc, char* argv[])
{
int sourcenum,a,b,c,i,timeslice;
Event* events = NULL;
if(argc != 3)
{
printf("Proper usage is: main.c sources time-slice\n");
exit(EXIT_FAILURE);
}
// TODO: these really should be using strtol() for better
// error detection. left as exercise for author.
sourcenum = atoi(argv[1]);
timeslice = atoi(argv[2]);
for(i = 0; i < sourcenum ; i++)
{
printf("please enter the process-id, arrival-time and cpu-time.\n");
if (scanf("%d %d %d",&a, &b, &c) == 3)
{
add_event(&events, create_node(a,b,c));
print_eventlist(events);
}
}
return 0;
}
// link an event on to the end of a linked list.
void add_event(Event** pp, Event* event)
{
while (*pp)
pp = &(*pp)->next;
*pp = event;
}
Event* create_node(int processid, int arrivaltime, int cputime)
{
Event *ptr = malloc(sizeof(*ptr));
if (ptr == NULL)
{
perror("Failed to allocate Event.");
exit(EXIT_FAILURE);
}
ptr->processid = processid;
ptr->arrivaltime = arrivaltime;
ptr->cputime = cputime;
ptr->next = NULL;
return ptr;
}
void print_node(const Event* node)
{
if (node != NULL)
{
printf("process-id = %d\n",node->processid);
printf("Arrival Time = %d\n",node->arrivaltime);
printf("CPU time = %d\n",node->cputime);
}
else
{
printf("NULL\n");
}
}
void print_eventlist(const Event* currentPtr)
{
puts("==========================================");
while(currentPtr != NULL)
{
print_node(currentPtr);
puts("==========================================");
currentPtr = currentPtr->next;
}
puts("NULL");
puts("==========================================");//list #%d\n",i);
}
please enter the process-id, arrival-time and cpu-time.
1 1 1
==========================================
process-id = 1
Arrival Time = 1
CPU time = 1
==========================================
NULL
==========================================
please enter the process-id, arrival-time and cpu-time.
2 2 2
==========================================
process-id = 1
Arrival Time = 1
CPU time = 1
==========================================
process-id = 2
Arrival Time = 2
CPU time = 2
==========================================
NULL
==========================================
please enter the process-id, arrival-time and cpu-time.
3 3 3
==========================================
process-id = 1
Arrival Time = 1
CPU time = 1
==========================================
process-id = 2
Arrival Time = 2
CPU time = 2
==========================================
process-id = 3
Arrival Time = 3
CPU time = 3
==========================================
NULL
==========================================
please enter the process-id, arrival-time and cpu-time.
4 4 4
==========================================
process-id = 1
Arrival Time = 1
CPU time = 1
==========================================
process-id = 2
Arrival Time = 2
CPU time = 2
==========================================
process-id = 3
Arrival Time = 3
CPU time = 3
==========================================
process-id = 4
Arrival Time = 4
CPU time = 4
==========================================
NULL
==========================================
please enter the process-id, arrival-time and cpu-time.
5 5 5
==========================================
process-id = 1
Arrival Time = 1
CPU time = 1
==========================================
process-id = 2
Arrival Time = 2
CPU time = 2
==========================================
process-id = 3
Arrival Time = 3
CPU time = 3
==========================================
process-id = 4
Arrival Time = 4
CPU time = 4
==========================================
process-id = 5
Arrival Time = 5
CPU time = 5
==========================================
NULL
==========================================