改正一段代码：#include <stdlib.h> #include <stdio.h> typedef struct Node { int data; struct Node* left; struct Node* right; }BiTreeNode,*BiTree; void Initiate(BiTree *root,DataType x){ *root=(BiTree)mallco(sizeof(BiTreeNode)); (*root)->data=x; (*root)->left=NULL; (*root)->right=NULL; } BiTree InsertLeftNode(BiTree curr,DataType x) { BiTree s,t; if(curr==NULL) return NULL; t=curr->left; s=(BiTree)mallloc(sizeof(BiTreeNode)); s->data=x; s->left=t; s->right=NULL; vurr->left=s; return curr->left; } BiTree InsertRightNode(BiTree curr.DataType x) { BiTree s,t; if(curr==NULL) return NULL; t=curr->right; s=(BiTree)mallloc(sizeof(BiTreeNode)); s->data=x; s->right=t; s->left=NULL; vurr->left=s; return curr->right; } typedef char DataType; void main(void) { InsertRightNode *root, *p; Initiate(&root); p = InsertLeftNode(root, 'A'); p = InsertLeftNode(p, 'B'); p = InsertLeftNode(p, 'D'); p = InsertRightNode(p, 'G'); p = InsertRightNode(root->left, 'C'); InsertLeftNode(p, 'E'); InsertRightNode(p, 'F'); } void PrintBiTree(BiTreeNode *bt, int n) { int i; if(bt == NULL) return; PrintBiTree(bt->right, n+1); for(i = 0; i < n-1; i++) printf(“ ”); // 打印3个空格 if(n > 0) { printf(“---”); printf(“%c\n”, bt->data); } PrintBiTree(bt->left, n+1); }

改正后的代码如下：

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

typedef char DataType;

typedef struct BiTreeNode {
    int data;
    struct BiTreeNode* left;
    struct BiTreeNode* right;
} BiTreeNode, *BiTree;

void Initiate(BiTree* root, DataType x) {
    *root = (BiTree)malloc(sizeof(BiTreeNode));
    (*root)->data = x;
    (*root)->left = NULL;
    (*root)->right = NULL;
}

BiTree InsertLeftNode(BiTree curr, DataType x) {
    BiTree s, t;
    if (curr == NULL) return NULL;
    t = curr->left;
    s = (BiTree)malloc(sizeof(BiTreeNode));
    s->data = x;
    s->left = t;
    s->right = NULL;
    curr->left = s;
    return curr->left;
}

BiTree InsertRightNode(BiTree curr, DataType x) {
    BiTree s, t;
    if (curr == NULL) return NULL;
    t = curr->right;
    s = (BiTree)malloc(sizeof(BiTreeNode));
    s->data = x;
    s->right = t;
    s->left = NULL;
    curr->right = s;
    return curr->right;
}

void PrintBiTree(BiTreeNode* bt, int n) {
    int i;
    if (bt == NULL) return;
    PrintBiTree(bt->right, n + 1);
    for (i = 0; i < n - 1; i++) printf("   "); // 打印3个空格
    if (n > 0) {
        printf("---");
        printf("%c\n", bt->data);
    }
    PrintBiTree(bt->left, n + 1);
}

int main(void) {
    BiTree root, p;
    Initiate(&root, 'A');
    p = InsertLeftNode(root, 'B');
    p = InsertLeftNode(p, 'D');
    p = InsertRightNode(p, 'G');
    p = InsertRightNode(root->left, 'C');
    InsertLeftNode(p, 'E');
    InsertRightNode(p, 'F');
    PrintBiTree(root, 0);
    return 0;
}