[問題] Linked list incompatible pointer type

[jeffchen106 (超哥)]

開發平台(Platform): (Ex: Win10, Linux, ...) 

Win10

編譯器(Ex: GCC, clang, VC++...)+目標環境(跟開發平台不同的話需列出)

https://www.onlinegdb.com/online_c_compiler


問題(Question)：

這個code主要是可以動態輸入資料並且創建出Linked list, 並且還能夠排序好.

這段code跑起來沒有問題, 能夠成功. 但不知道為什麼在上面提到的編譯器編譯
時一直出現多行warning: incompatible pointer size. 舉其中兩例如下:
newNodePtr->NextPtr = Headnode;
CurrentPtr = CurrentPtr->NextPtr;

希望能有熱心的高手指點我一下，非常謝謝

錯誤結果(Wrong Output)：
擷取部分:
main.c:33:29: warning: assignment from incompatible pointer type
[-Wincompatible-pointer-types]
main.c:40:20: warning: assignment from incompatible pointer type
[-Wincompatible-pointer-types]
main.c:44:29: warning: assignment from incompatible pointer type
[-Wincompatible-pointer-types]
main.c:45:30: warning: assignment from incompatible pointer type
[-Wincompatible-pointer-types]
main.c:50:29: warning: assignment from incompatible pointer type
[-Wincompatible-pointer-types]


程式碼(Code)：(請善用置底文網頁, 記得排版，禁止使用圖檔) 

// Online C compiler to run C program online
#include <stdio.h>
#include
<stdlib.h>
typedef struct node
{
    int data;
    int *NextPtr;
}Node;

Node *Headnode;
void insert_node(int element)
{
    Node *PreviousPtr;
    Node *CurrentPtr;
    Node *newNodePtr = malloc(sizeof(Node));
    Node *tempNode;

    if(newNodePtr == NULL)
    {
        printf("Not enough space!");

        return;
    }
    newNodePtr->data = element;
    newNodePtr->NextPtr = NULL;

    CurrentPtr = Headnode;

    if(Headnode == NULL)
    {

        Headnode = newNodePtr;
        return;
    }
    if(element < Headnode->data)

    {
        newNodePtr->NextPtr = Headnode;
        Headnode = newNodePtr;

        return;
    }
    while((element > (CurrentPtr->data)) && ((CurrentPtr->NextPtr) != NULL))
    {
        PreviousPtr = CurrentPtr;

        CurrentPtr = CurrentPtr->NextPtr;
    }
    if(CurrentPtr->data > element)

    {
        newNodePtr->NextPtr = CurrentPtr;
        PreviousPtr->NextPtr = newNodePtr;
    }
    else
    {
        newNodePtr->NextPtr = CurrentPtr->NextPtr;
        CurrentPtr->NextPtr = newNodePtr;
    }


        return;
}

void Print_node()
{
    Node *Currentnode;
    Currentnode = Headnode;
    printf(" %d -->", Currentnode->data);

    while(Currentnode->NextPtr !=NULL)
    {
        Currentnode = Currentnode->NextPtr;
        printf(" %d -->", Currentnode->data);
    }

    if(Currentnode->NextPtr == NULL)
        printf("NULL");
}

int main()
{

    int choice = 0;
    int element;
    Headnode = NULL;
    int del_result;

    printf("Enter your choice:\n");
    printf("1 to insert an element into the list\n");
    printf("2 to delete an element from the list\n");
    printf("3 to end");
    while(choice != 3)
    {
        printf("\n?");

        scanf("\n%d", &choice);
        switch(choice)
        {
            case 1:

                printf("Enter a integer: ");
                scanf("%d", &element);
                insert_node(element);
                Print_node();

                break;
            case 3:
                printf("End of Run");
                break;
        }
    }
    return 0;
}


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※ 文章網址: https://www.ptt.cc/bbs/C_and_CPP/M.1631879624.A.1E2.html
※ 編輯: jeffchen106 (219.71.109.75 臺灣), 09/17/2021 19:54:14
推 j0958322080: 看起來是你的 next 型別那邊有問題
推 gusion: 你的NextPtr是指到int，應該要指到struct node才對
→ jeffchen106: 對不起不是很懂>< 像第33行報warning的那邊,NextPtr
→ jeffchen106: 指到的是Headnode,那應該也算是指到struct node啊?
推 pponywong: int* NextPtr; 改成 struct node* NextPtr;
→ sarafciel: 你把月餅塞進巧克力蛋糕的紙盒拿去送人  就定義上來說
→ pponywong: 這個用法是 struct 裡面宣告 struct pointer type
→ sarafciel: 你還是送了月餅沒錯 但人家會疑惑怎麼用巧克力蛋糕的外
→ sarafciel: 盒也是很合理的呀
→ wawi2: 用dummy head可以解決你code裡的一堆NULL check
→ jeffchen106: 感謝各位！我放進月餅盒之後果然warning解除了！