版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/Ming991301630/article/details/82381506
```
class Solution {
private:
TreeNode * getTheTree(vector<int>& pre, vector<int>& vin, int pi, int pj, int vi, int vj) {
if (pi > pj || vi > vj)return nullptr;
int i;
for (i = vi; i <= vj; ++i) {//找到根节点在中序数组中的位置
if (pre[pi] == vin[i]) {
break;
}
}
TreeNode* root = new TreeNode(pre[pi]);
root->left = getTheTree(pre, vin, pi + 1, pi + i - vi, vi, i - 1);
//第二参数: pi + i - vi = pi + 1 + (i - 1 - vi)
root->right = getTheTree(pre, vin, pi + i - vi + 1, pj, i + 1, vj);
//第一参数: pi + i - vi + 1 = (pi + i - vi) + 1[上面第二参数+1]
return root;
}
public:
TreeNode * reConstructBinaryTree(vector<int> pre, vector<int> vin) {
return getTheTree(pre, vin, 0, pre.size() - 1, 0, vin.size() - 1);
}
};