-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathquestion7.cpp
More file actions
45 lines (41 loc) · 1.26 KB
/
Copy pathquestion7.cpp
File metadata and controls
45 lines (41 loc) · 1.26 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
/*
输入某二叉树的前序遍历和中序遍历的结果，请重建出该二叉树。
假设输入的前序遍历和中序遍历的结果中都不含重复的数字。
例如输入前序遍历序列{1,2,4,7,3,5,6,8}和中序遍历序列{4,7,2,1,5,3,8,6}，则重建二叉树并返回。
Xiaobin Tian;
*/
#include<vector>
using namespace::std;
struct TreeNode {
int val;
TreeNode *left;
TreeNode *right;
TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};
class Solution {
public:
TreeNode* reConstructBinaryTree(vector<int> pre,vector<int> vin) {
if(vin.size() == 0){
return NULL;
}
TreeNode *head = new TreeNode(pre[0]);
vector<int> pre_left, pre_right, vin_left, vin_right;
int i = 0;
for(; i < vin.size(); ++i){
if(vin[i] == pre[0]){
break;
}
pre_left.push_back(pre[i+1]);
vin_left.push_back(vin[i]);
}
++i;
for(; i < vin.size(); ++i){
pre_right.push_back(pre[i]);
vin_right.push_back(vin[i]);
}
head->left = reConstructBinaryTree(pre_left, vin_left);
head->right = reConstructBinaryTree(pre_right, vin_right);
return head;
}
};