C语言：使用结构实现二叉搜索树时出错

Question

/* These are struct definitions I am using */
struct PdsNdxInfo{
    int key;
    int offset;
};

struct PdsInfo{
    FILE *repo_fptr;
    FILE *ndx_fptr;
    char repo_name[MAX_NAME_LEN];
    int repo_status;  
    int num_recs;
    struct PdsNdxInfo ndxEntries[MAX_RECS];
};


/*This is the code */

//BST Creation
struct PdsNdxInfo temp[pdsInfo.num_recs];
fseek(pdsInfo.ndx_fptr,0,SEEK_SET);
fread(temp, sizeof(struct  PdsNdxInfo), pdsInfo.num_recs, pdsInfo.ndx_fptr);


int i=0;
while(i < pdsInfo.num_recs){
    printf("********%d  %d",temp[i].key,temp[i].offset);
    if(root==NULL) {
        root =insert(root,temp[i].key,temp[i].offset); //getting error
    }
    else {
        insert(root,temp[i].key,temp[i].offset);
    }
    i++;    
}

/* This is the function definition */
struct node *newNode(int k,int o){
    struct node *temp =  (struct node *)malloc(sizeof(struct node));
    temp->key = k;temp->offset = o;
    temp->left = temp->right = NULL;
    return temp;
}

struct node* insert(struct node* root, int k,int o) {
    if (root == NULL) return newNode(k,o);
    if (k < root->key)
    root->left  = insert(root->left, k,o);
    else if (k > root->key)
    root->right = insert(root->right, k,o);   

    return root;
}

编译器错误：

pds_version2.c: In function ‘pds_store’:
pds_version2.c:119:9: warning: assignment makes pointer from integer 
without a cast [enabled by default]
root = insert(root,pdsInfo.ndxEntries[pdsInfo.num_recs-
1].key,pdsInfo.ndxEntries[pdsInfo.num_recs-1].offset);
     ^
pds_version2.c: At top level:
pds_version2.c:180:14: error: conflicting types for ‘insert’
struct node* insert(struct node* root, int k,int o)
          ^
pds_version2.c:66:10: note: previous implicit declaration of ‘insert’ 
was here
root =insert(root,temp[i].key,temp[i].offset);

基本上无法弄清楚为什么会发生错误我正在尝试创建二叉搜索树，以上是插入和新节点这两种方法，但出现编译时错误。

新节点是一个结构体，有左右两个指针和两个数据值。但我无法弄清楚为什么会出现这样的错误 "assignment makes pointer from integer without a cast [enabled by default]"

Answer 1

您应该将插入功能放在使用它的地方之前。或者干脆把函数声明放在前面：

struct node* insert(struct node* root, int k,int o);

void code()
{
  //use insert function here
}
struct node* insert(struct node* root, int k,int o)
{
  //insert function definition
}

C语言：使用结构实现二叉搜索树时出错

C Language : Error in implementing binary search tree using structures

c

struct

function-pointers

file

binary-search-tree