从文件创建链接列表并重置头部

For an assignment I'm creating a program where a text file is read and used to create a linkedlist. I'm having issues resetting the head of the list back to its original point after all the elements have been added. I have tried assigning the head pointer to some temp pointer and reassigning it at the end but that just leads to head only pointing to the first element and the ->next is null. For an assignment I'm creating a program where