关于“ multiple definition of `generate(int, DLList)'”
写了三个文件：一个.h,两个cpp
dllist.h:
class DLLElement {
public:
DLLElement( void *itemPtr, int sortKey ); // initialize a list element
DLLElement *next; // next element on list
// NULL if this is the last
DLLElement *prev; // previous element on list
// NULL if this is the first
int key; // priority, for a sorted list
void *item; // pointer to item on the list
};
class DLList {
public:
DLList(); // initialize the list
~DLList(); // de-allocate the list
void Prepend(void *item); // add to head of list (set key = min_key-1)
void Append(void *item); // add to tail of list (set key = max_key+1)
void *Remove(int *keyPtr); // remove from head of list
// set *keyPtr to key of the removed item
// return item (or NULL if list is empty)
bool IsEmpty(); // return true if list has elements
// routines to put/get items on/off list in order (sorted by key)
void SortedInsert(void *item, int sortKey);
void *SortedRemove(int sortKey); // remove first item with key==sortKey
// return NULL if no such item exists
private:
DLLElement *first; // head of the list, NULL if empty
DLLElement *last; // last element of the list, NULL if empty
};
dllist.cc:
extern "C" {
#include <assert.h>
#define ASSERT(expression) assert(expression)
}
#include <iostream>
#include "dllist.h"
using namespace std;
DLLElement::DLLElement(void *itemPtr, int sortKey )
{
item=itemPtr;
key=sortKey;
next=prev=NULL;
}
DLList::DLList()
{
first=NULL;
last=NULL;
}
DLList::~DLList()
{
DLLElement *p,*q;
q=p=first;
while(p!=NULL)
{
q=p->next;
delete[]p;
p=q;
}
}
void DLList::Prepend(void *item)
{
DLLElement *q;
q=first;
q->prev=(DLLElement *)item;
((DLLElement *)item)->next=q;
((DLLElement *)item)->prev=NULL;
((DLLElement *)item)->key=q->key-1;
first=(DLLElement *)item;
}
void DLList::Append(void *item)
{
DLLElement *q;
q=last;
q->next=(DLLElement *)item;
((DLLElement *)item)->prev=q;
((DLLElement *)item)->next=NULL;
((DLLElement *)item)->key=last->key+1;
last=(DLLElement *)item;
}
bool DLList::IsEmpty()
{
if(last==first)
return 0;
else
return 1;
}
void * DLList::Remove(int *keyPtr)
{
DLLElement *q,*p;
p=first;
if(!p)
return NULL;
else
{
keyPtr=&p->key;
q=first->next;
p->next=NULL;
q->prev=NULL;
first=q;
return p;
}
}
void DLList::SortedInsert(void *item, int sortKey)
{
DLLElement *p,*q;
p=first;
q->item=item;
q->key=sortKey;
while(p!=NULL)
{
if(sortKey>=p->key)
p++;
else
{
if((p!=first)&&(p!=last))
{
p->prev->next=q;
q->prev=p->prev;
q->next=p;
p->prev=q;
}
else if(p==first)
{
p->prev=q;
q->next=p;
q->prev=NULL;
first=q;
}
else
{
p->next=q;
q->prev=p;
q->next=NULL;
last=q;
}
}
}
}
void * DLList::SortedRemove(int sortKey)
{
DLLElement *p;
p=first;
while(p!=NULL)
{
if(p->key==sortKey)
{
if((p!=first)&&(p!=last))
{
p->prev->next=p->next;
p->next->prev=p->prev;
}
else if(p==first)
{
p->next=first;
p->next->prev=NULL;
}
else
{
p->prev=last;
p->prev->next=NULL;
}
return p;
}
else
p++;
}
if(p==NULL)
return NULL;
}
dllist-driver.cc:
#include "dllist.h"
#include <iostream>
#include <ctime>
#include <cstdlib>
using namespace std;
void generate(int n,DLList m)
{
int i,keyword,*it;
//DLLElement *q;
srand((unsigned)time(0));
for(i=0;i<n;i++)
{
keyword=rand()%n;
it=&keyword;
//DLLElement *p=new DLLElement(,keyword);
m.SortedInsert(it,keyword);
}
}
void move(int n,DLList m)
{
int i,*keyPtr;
for(i=0;i<n;i++)
{
cout<<m.Remove(keyPtr)<<endl;
}
}
int main()
{
int a;
DLList u;
printf("请输入队列元素个数：\n");
scanf("%d",&a);
generate(a,u);
move(a,u);
return 0;
}
在最终编译时出现错误：
D:\MinGWStudio\MinGW\lib\lianbiao\Debug\dllist-driver.o: In function `Z8generatei6DLList':D:\MinGWStudio\MinGW\lib\lianbiao\dllist-driver.cpp:11: multiple definition of `generate(int, DLList)'
D:\MinGWStudio\MinGW\lib\lianbiao\Debug\dllist-driver.o:D:\MinGWStudio\MinGW\lib\lianbiao\dllist-driver.cpp:11: first defined here
D:\MinGWStudio\MinGW\lib\lianbiao\Debug\dllist-driver.o: In function `Z4movei6DLList':D:\MinGWStudio\MinGW\lib\lianbiao\dllist-driver.cpp:31: multiple definition of `move(int, DLList)'
D:\MinGWStudio\MinGW\lib\lianbiao\Debug\dllist-driver.o:D:\MinGWStudio\MinGW\lib\lianbiao\dllist-driver.cpp:31: first defined here
D:\MinGWStudio\MinGW\lib\lianbiao\Debug\dllist-driver.o: In function `main':D:\MinGWStudio\MinGW\lib\lianbiao\dllist-driver.cpp:40: multiple definition of `main'
D:\MinGWStudio\MinGW\lib\lianbiao\Debug\dllist-driver.o:D:\MinGWStudio\MinGW\lib\lianbiao\dllist-driver.cpp:40: first defined here
collect2: ld returned 1 exit status
也查找了网上的一些资料，但是可能是不会修改，还是有错，只能贴上一群代码，求助大牛们…… c++
[解决办法]
generate、 move 重名了。
cstdlib库中有同名函数，最好改下名字.
[解决办法]
另main不该有多处同名的，
//dllist-driver.cc:
如果你有多处引用的话，最好加上名字空间，并且加上
#ifndef dllist-driverCC
#define dllist-driverCC
.....你的代码,
#endif
[解决办法]
你注释掉generate、 move两个函数的定义，
用 CTRL + 鼠标左键 , 点调用generate函数的地方，这时IDE会查找该函数的头文件。
