在写一个添加新元素的程序,要求是将元素添加,然后将光标(个人认为就是curr,现在值)移到新添加数的后面,成功就return1,(例子如下).否则0,这里我不是很理解什么时候是0的情况,如果有大神清楚,请讲解

例子:add 20, returns 1
      ............................
       20   ^  
      ............................
    add 12, returns 1
      ............................
       20   12   ^  
      ............................
    add 33, returns 1
      ............................
       20   12   33   ^  


以下是我目前渣出来的程序,add那里一塌糊涂,并不知道怎么弄

#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include "listIteratorInt.h"

typedef struct Node {

  // implement struct here .. 
    int value;
    struct Node *next;
    struct Node *prev;
  
} Node;

typedef struct IteratorIntRep {

  // implement struct here .. 
    int nitems;
    struct IteratorIntRep *first;
    struct IteratorIntRep *last;
    struct IteratorIntRep *curr;
    
} IteratorIntRep;

IteratorInt IteratorIntNew(){

  // implement this function 
    struct IteratorIntRep *it;
    
    it = malloc(sizeof (struct IteratorIntRep));
    assert (it != NULL);
    it->nitems = 0;
    it->first = NULL;
    it->last = NULL;
    it->curr = NULL;
           
    return it;  // you need to change this...
}

int add(IteratorInt it, int v){
  
  // implement this function
    Node *new;
    new = malloc(sizeof(Node));
  
    new->value = v;
    new->next = NULL;
    it->next = new->next;
    it->curr = new->next;
  
  return 0;  // you need to change this...
}


int hasNext(IteratorInt it){
  
  if(it->curr->next != NULL){
    return 1;
  } else{ return 0;} 
  // implement this function 
  
  // you need to change this...
}

int hasPrevious(IteratorInt it){
  
  if(it->prev != NULL){
    return 1;
  } else{ return 0;}

  // implement this function 
  
    // you need to change this...
}

之后我在测的时候出现以下错误:listIteratorInt.c: In function 'add':
listIteratorInt.c:72:7: error: 'struct IteratorIntRep' has no member named 'next'
     it->next = new->next;
       ^
listIteratorInt.c:73:14: error: assignment from incompatible pointer type [-Werror]
     it->curr = new->next;
              ^
listIteratorInt.c: In function 'hasNext':
listIteratorInt.c:81:14: error: 'struct IteratorIntRep' has no member named 'next'
   if(it->curr->next != NULL){
              ^
listIteratorInt.c: In function 'hasPrevious':
listIteratorInt.c:91:8: error: 'struct IteratorIntRep' has no member named 'prev'
   if(it->prev != NULL){
        ^
想问一下这里要怎么设curr,要怎么改正?
以上是我所有困惑,请高人指点,谢谢!!

[此贴子已经被作者于2016-4-13 13:24编辑过]

你看不懂英文吗？说得很清楚了，代码把两个结构体搞混了，成员就不配对了。

[此贴子已经被作者于2016-4-13 13:28编辑过]

所以就是把next和curr的typedef位置换一下吗.....表示完全不懂啊

typedef struct IteratorIntRep {

  // implement struct here .. 
    int nitems;
    struct Node *first;  //这里first,last,curr应该是Node*吧，不然IteratorIntRep*=Node*,强制转换？
    struct Node *last;
    struct Node *curr;
    
} IteratorIntRep;

恩, 这里这样好像是对的,谢谢,可是上面那个呢?这两个区别在哪.......

first,last,curr是IteratorIntRep*的话真看不懂，因为first,last,curr都是要指向Node*结点的

其实我也真不懂....我是看到其他类似程序第二个是这样的.....

struct IntListNode {
    int  data;  // value of this list item
    struct IntListNode *next;
                // pointer to node containing next element
};

struct IntListRep {
    int  size;  // number of elements in list
    struct IntListNode *first;
                // node containing first value
    struct IntListNode *last;
                // node containing last value
};

那需要把next和prev也写到第二个typedef里吗?谢谢回答!!!

不需要，像4楼那样就行

可是它有显示这个:
listIteratorInt.c: In function 'add':
listIteratorInt.c:72:7: error: 'struct IteratorIntRep' has no member named 'next'
     it->next = new->next;
       ^
listIteratorInt.c: In function 'hasPrevious':
listIteratorInt.c:91:8: error: 'struct IteratorIntRep' has no member named 'prev'
   if(it->prev != NULL){
        ^
------------------------------
还有那个,能顺便看一下add要怎么弄吗,无从下手啊.........非常感谢

IteratorInt IteratorIntNew(){

  // implement this function 
    struct IteratorIntRep *it;
    
    it = malloc(sizeof (struct IteratorIntRep));
    assert (it != NULL);
    it->nitems = 0;
    it->first = NULL;
    it->last = NULL;
    it->curr = NULL;
           
    return it;  // you need to change this...
}

int add(IteratorInt it, int v){
  
  // implement this function
    Node *new;
    new = malloc(sizeof(Node));
    
    new->value = v;
    new->next = it->curr->next;
    it->curr->next->prev=new;
    it->curr->next=new;
    new->prev=it->curr;
    it->curr=it->curr->next;
  
  return 0;  // you need to change this...
}


int hasNext(IteratorInt it){
  
  if(it->curr->next != NULL){
    return 1;
  } else{ return 0;} 
  // implement this function 
  
  // you need to change this...
}

int hasPrevious(IteratorInt it){
  
  if(it->curr->prev != NULL){
    return 1;
  } else{ return 0;}

  // implement this function 
  
    // you need to change this...
}