Question

用C语言编程实现二叉树的基本操作，并完成下述函数功能： (1) CreateBiTree( )：根据先序遍历序列生成一棵

Answer 1

下面有一个建树的例子。
class TreeNode{
public:
TreeNode *left;
TreeNode *right;
int value;
TreeNode(int v): value(v)
{
left = NULL;
right = NULL;
}
~TreeNode() {
if (left != NULL) delete left;
if (right != NULL) delete right;
}
};

void addToTree(TreeNode *curr, TreeNode *p) {
if(p->value <= curr->value) {
if(curr->left == NULL) {
curr->left = p;
return;
}
else addToTree(curr->left, p);
} else {
if(curr->right == NULL) {
curr->right = p;
return;
}
else addToTree(curr->right, p);
}
}
void printTree(TreeNode *p) {
if(p==NULL) return;
printTree(p->left);
printf("%d ", p->value);
printTree(p->right);
}
TreeNode * createBiTree(int[] a, int len)
{
TreeNode *root = new TreeNode(a[0]);
for(int i=1; i<5; i++) {
TreeNode *p = new TreeNode(a[i]);
addToTree(root, p);
}
return root;
}

void main() {
int a[] = {3, 4, 1, 2, 5};
CreateBiTeee(a, 5);
printTree(root);
delete root;
}

Answer 2

递归创建，很简单的，自己做吧，书上肯定有~

Answer 3

我是学pascal的。