/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
TreeNode* buildTree(vector<int>& preorder, vector<int>& inorder) {
if(preorder.empty()) return NULL;
return helper(preorder, 0, preorder.size()-1, inorder, 0, inorder.size()-1);
}
TreeNode* helper(vector<int>& preorder, int pl, int pr, vector<int>& inorder, int il, int ir){
if(pl>pr || il>ir) return NULL;
int cur_val = preorder[pl];
TreeNode* cur = new TreeNode(cur_val);
int found = find(inorder.begin()+il, inorder.begin()+ir, cur_val)-(inorder.begin()+il);
cur->left = helper(preorder, pl+1, pl+found, inorder, il, il+found-1);
cur->right = helper(preorder, pl+1+found, pr, inorder, il+1+found, ir);
return cur;
}
};
LeetCode - Construct Binary Tree from Preorder and Inorder Traversal
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转载自blog.csdn.net/real_lisa/article/details/83055817
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