LeetCode105 Construct Binary Tree from Preorder and Inorder Traversal

题目链接：

https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/

题目描述：

前序中序建树。

题目分析：

就是先建立好根节点，再根据这个根节点递归的不停的划分左右子树。

代码：

void createBinaryTree(struct TreeNode* *root, int* preorder, int* inorder, int len){
    for (int i = 0; i<len; i++){
        if (preorder[0] == inorder[i]){
            *root = (struct TreeNode*)malloc(sizeof(struct TreeNode*));
            (*root)->val = preorder[0];
            (*root)->left = (*root)->right = NULL;
            createBinaryTree(&((*root)->left), preorder + 1, inorder, i);
            createBinaryTree(&((*root)->right), preorder + i + 1, inorder+i+1, len - i - 1);
            break;
        }
    }
}
struct TreeNode* buildTree(int* preorder, int preorderSize, int* inorder, int inorderSize) {
    struct TreeNode* root = NULL;
    createBinaryTree(&root, preorder, inorder, inorderSize);
    return root;
}