c++出现expected primary-expression before '&' token;是什么原因

Question

#include <iostream>
#include <stdlib.h>
using namespace std;

#define INIT_SIZE 100
#define INC_SIZE 10

//定义一个线性表
typedef struct
{
int *elems;
int len;
int size;
}ArrayList;

//初始化线性表
void init(ArrayList&list)
{
list.elems=(int *)malloc(sizeof(int)*INIT_SIZE);
list.len=0;
list.size=INIT_SIZE;
}

//打印顺序表
void print(ArrayList& list)
{
for (int i = 0; i < list.len; i++)
{
cout<<list.elems[i]<<"\n";
}
}

//销毁顺序表
void destroy(ArrayList& list)
{
free(list.elems);
list.len = 0;
list.size = 0;
}

//向顺序表index位置插入元素

void insert(ArrayList&list,int index,int e)
{
if(list.len>=list.size)
list.elems=(int *)realloc(list.elems, sizeof(int) * (INC_SIZE + list.size));

for(int i=list.len-1;i>=index;i--)
{
list.elems[i+1]=list.elems[i];
}

list.elems[index] = e;
list.len++;
}

//向顺序表末尾插入元素e
void add(ArrayList& list, int e)
{
insert(list, list.len, e);
}

//删除顺序表index位置的元素
void remove(ArrayList&list,int index)
{
for(int i=index;i<=list.len-2;i++)
{
list.elems[i]=list.elems[i+1];
}
list.len--;
}

//将1，2比较然后放入3中的函数
void merge(ArrayList&list1,ArrayList& list2,ArrayList& list3)
{
init(list3);
int *i,*j;int k=0;
i=ArrayList& list1;
j=ArrayList& list2;

for(int s=1;s<=ArrayList&list1.len && s<=ArrayList&list2.len;s++,i++,j++)
if(*i<*j)
{
insert(ArrayList&list3,k++,*i);
}
else insert(ArrayList&list3,k++,*j);
}

void testBasic()
{

init(ArrayList&list1);
init(ArrayList&list2);
init(ArrayList&list3);
add(ArrayList&list1, 3);
add(ArrayList&list1, 7);
add(ArrayList&list2, 2);
add(ArrayList&list2, 4);
add(ArrayList&list2, 5);
merge(ArrayList&list1, ArrayList&list2, ArrayList&list3);
print(ArrayList&list3);
destroy(ArrayList&list1);destroy(ArrayList&list2);destroy(ArrayList&list3);
}

int main()
{
testBasic();
}

Answer 1

//修改编译错误的办法：
//所有提示expected primary-expression before '&' token;的地方
//都把ArrayList&删掉
//以及将i和j的赋值语句改为i=list1.elems;j=list2.elems;

#include <iostream>
#include <stdlib.h>
using namespace std;

#define INIT_SIZE 100
#define INC_SIZE 10

//定义一个线性表
typedef struct
{
int *elems;
int len;
int size;
}ArrayList;

ArrayList list1, list2, list3;

//初始化线性表
void init(ArrayList&list)
{
list.elems=(int *)malloc(sizeof(int)*INIT_SIZE);
list.len=0;
list.size=INIT_SIZE;
}

//打印顺序表
void print(ArrayList& list)
{
for (int i = 0; i < list.len; i++)
{
cout<<list.elems[i]<<"\n";
}
}

//销毁顺序表
void destroy(ArrayList& list)
{
free(list.elems);
list.len = 0;
list.size = 0;
}

//向顺序表index位置插入元素

void insert(ArrayList&list,int index,int e)
{
if(list.len>=list.size)
list.elems=(int *)realloc(list.elems, sizeof(int) * (INC_SIZE + list.size));

for(int i=list.len-1;i>=index;i--)
{
list.elems[i+1]=list.elems[i];
}

list.elems[index] = e;
list.len++;
}

//向顺序表末尾插入元素e
void add(ArrayList& list, int e)
{
insert(list, list.len, e);
}

//删除顺序表index位置的元素
void remove(ArrayList&list,int index)
{
for(int i=index;i<=list.len-2;i++)
{
list.elems[i]=list.elems[i+1];
}
list.len--;
}

//将1，2比较然后放入3中的函数
void merge(ArrayList&list1,ArrayList& list2,ArrayList& list3)
{
init(list3);
int *i,*j;int k=0;
i=list1.elems;
j=list2.elems;

for(int s=1;s<=list1.len && s<=list2.len;s++,i++,j++)
if(*i<*j)
{
insert(list3,k++,*i);
}
else insert(list3,k++,*j);
}

void testBasic()
{

init(list1);
init(list2);
init(list3);
add(list1, 3);
add(list1, 7);
add(list2, 2);
add(list2, 4);
add(list2, 5);
merge(list1, list2, list3);
print(list3);
destroy(list1);destroy(list2);destroy(list3);
}

int main()
{
testBasic();
}

Answer 2

你这错误太多了。ArrayList&和list之间不应该空一格么？类型和变量名要分隔开。i = ArrayList& list1;是什么？赋值的同时声明一个变量么？猜测你是想用强制类型转换，你要这样写：i = (ArrayList) &list1;

Answer 3

服了你，testBasic中，你照抄声明有什么用，你定义变量啊。比如
ArrayList list1,list2,list3;
使用变量：
init(list1);
init(list2);
init(list3);其他类似