链表交换，输入后输出为空白

问题遇到的现象和发生背景

问题相关代码，请勿粘贴截图

#include<stdio.h>
#include<stdlib.h>
#define Type int
struct list{
    Type data;
    struct list * nextptr;
};
typedef struct list LIST;
typedef LIST * LISTPTR;
LIST * createlist(LISTPTR headptr);
void FindAndSwap(LISTPTR currentptr);
void printlist(LISTPTR currentptr);
void freelist(LISTPTR headptr);
int main(void)
{
    int ss1,ss2,tt1,tt2;
    LISTPTR headptr=NULL;
    headptr=createlist(headptr);
    FindAndSwap(headptr);
    printlist(headptr);
    freelist(headptr);
    return 0;
}
LIST * createlist(LISTPTR headptr)
{
    LISTPTR currentptr,newptr;
    int num;
    newptr=malloc(sizeof(LISTPTR));
    newptr->nextptr=NULL;
    headptr=newptr;
    scanf("%d",&num);
    while(num!=-1){
        newptr=malloc(sizeof(LIST));
        newptr->data=num;
        newptr->nextptr=NULL;
        if(headptr->nextptr==NULL){
            currentptr=newptr;
            headptr->nextptr=currentptr;
        }
        else{
            currentptr->nextptr=newptr;
            currentptr=newptr;
        }
        scanf("%d",&num);
    }
    return headptr;
}
void FindAndSwap(LISTPTR currentptr)
{
    int a,s1,s2,t1,t2;
    scanf("%d %d %d %d",&s1,&t1,&s2,&t2);
    a=0;
    LISTPTR preptr1,preptr2,tptr1,tptr2,tptr3,tptr4,afterptr1,afterptr2;
    currentptr=currentptr->nextptr;
    while(currentptr!=NULL){
        a+=1;
        if(a==s1){
            tptr1=currentptr;
            preptr1->nextptr=currentptr;
        }
        if(a==t1){
            tptr2=currentptr;
            afterptr1=tptr2->nextptr;
        }
        if(a==s2){
            tptr3=currentptr;
            preptr2->nextptr=currentptr;
        }
        if(a==t2){
            tptr4=currentptr;
            afterptr2=tptr4->nextptr;
        }
        currentptr=currentptr->nextptr;
    }
    if(t1!=s2-1){
        tptr2->nextptr=afterptr2;
        preptr2->nextptr=tptr1;
        tptr4->nextptr=afterptr1;
        preptr1->nextptr=tptr2;
    }
    else if(t1==s2-1){
        tptr2->nextptr=afterptr2;
        tptr4->nextptr=tptr1;
        preptr1->nextptr=tptr3;
    }
}
void printlist(LISTPTR currentptr)
{
    currentptr=currentptr->nextptr;
    printf("The new list is:");
    while(currentptr!=NULL){
        if(currentptr->nextptr!=NULL){
            printf("%d ",currentptr->data);
        }
        else if(currentptr->nextptr==NULL){
            printf("%d\n",currentptr->data);
        }
        currentptr=currentptr->nextptr;
    }
}
void freelist(LISTPTR headptr)
{
    LISTPTR temptr;
    while(headptr!=NULL){
        temptr=headptr;
        headptr=headptr->nextptr;
        free(temptr);
    }
}

运行结果及报错内容

输入数据后运行不出来，我认为是那个FindAndSort函数有问题

我的解答思路和尝试过的方法

我想要达到的结果输入:1 2 3 4 5 6 7 8 9 10 -1

                                              1 1 4 7

输出：The new list is:4 5 6 7 2 3 1 8 9 10

newptr=malloc(sizeof(LISTPTR));
这就错了，sizeof(LIST)才行