输入文件到BST

Question

我在尝试将输入文件实现到二叉搜索树和输出时遇到了麻烦。我将在下面编写我的代码，但我不知道在哪里添加输入文件。在我的代码中我有4个选项，我不需要那些。另外我不知道如何使用getopt选项，我还没有理解这个概念。以及如何在对输出文件进行遍历后释放内存？

    # include <stdio.h>
    # include <stdlib.h>

    typedef struct BST {
       int data;
       struct BST *lchild, *rchild;
    } node;

    void insert(node *, node *);
    void inorder(node *);
    void preorder(node *);
    void postorder(node *);
    node *search(node *, int, node **);

    int main() {
       int choice;
       char ans = 'N';
       int key;
       node *new_node, *root, *tmp, *parent;
       node *get_node();
       root = NULL;
       //clrscr();

       printf("\nProgram For Binary Search Tree ");
       do {
          printf("\n1.Create");
          printf("\n2.Search");
          printf("\n3.Recursive Traversals");
          printf("\n4.Exit");
          printf("\nEnter your choice :");
          scanf("%d", &choice);

          switch (choice) {
          case 1:
             do {
                new_node = get_node();
                printf("\nEnter The Element ");
                scanf("%d", &new_node->data);

                if (root == NULL) /* Tree is not Created */
                   root = new_node;
                else
                   insert(root, new_node);

                printf("\nWant To enter More Elements?(y/n)");
               // ans = getch();
             } while (ans == 'y');
             break;

          case 2:
             printf("\nEnter Element to be searched :");
             scanf("%d", &key);

             tmp = search(root, key, &parent);
             printf("\nParent of node %d is %d", tmp->data, parent->data);
             break;

          case 3:
             if (root == NULL)
                printf("Tree Is Not Created");
             else {
                printf("\nThe Inorder display : ");
                inorder(root);
                printf("\nThe Preorder display : ");
                preorder(root);
                printf("\nThe Postorder display : ");
                postorder(root);
             }
             break;
          }
       } while (choice != 4);

    }

    /*
     Get new Node
     */
    node *get_node() {
       node *temp;
       temp = (node *) malloc(sizeof(node));
       temp->lchild = NULL;
       temp->rchild = NULL;
       return temp;
    }
    /*
     This function is for creating a binary search tree
     */
    void insert(node *root, node *new_node) {
       if (new_node->data < root->data) {
          if (root->lchild == NULL)
             root->lchild = new_node;
          else
             insert(root->lchild, new_node);
       }

       if (new_node->data > root->data) {
          if (root->rchild == NULL)
             root->rchild = new_node;
          else
             insert(root->rchild, new_node);
       }
    }
    /*
     This function is for searching the node from
     binary Search Tree
     */
    node *search(node *root, int key, node **parent) {
       node *temp;
       temp = root;
       while (temp != NULL) {
          if (temp->data == key) {
             printf("\nThe %d Element is Present", temp->data);
             return temp;
          }
          *parent = temp;

          if (temp->data > key)
             temp = temp->lchild;
          else
             temp = temp->rchild;
       }
       return NULL;
    }
    /*
     This function displays the tree in inorder fashion
     */
    void inorder(node *temp) {
       if (temp != NULL) {
          inorder(temp->lchild);
          printf("%d", temp->data);
          inorder(temp->rchild);
       }
    }
    /*
     This function displays the tree in preorder fashion
     */
    void preorder(node *temp) {
       if (temp != NULL) {
          printf("%d", temp->data);
          preorder(temp->lchild);
          preorder(temp->rchild);
       }
    }

    /*
     This function displays the tree in postorder fashion
     */
    void postorder(node *temp) {
       if (temp != NULL) {
          postorder(temp->lchild);
          postorder(temp->rchild);
          printf("%d", temp->data);
       }
    }