标签：val etc tree should res amp col blog binary
Given a binary search tree and the lowest and highest boundaries as L and R, trim the tree so that all its elements lies in [L, R] (R >= L). You might need to change the root of the tree, so the result should return the new root of the trimmed binary search tree.
Example 1:
Input:
1
/ 0 2
L = 1
R = 2
Output:
1
2
Example 2:
Input:
3
/ 0 4
2
/
1
L = 1
R = 3
Output:
3
/
2
/
1
思路：
递归即可。
TreeNode* trimBST(TreeNode* root, int L, int R) { if (root == NULL || L>R)return NULL; if (root->val == L) { root->left = NULL; root->right = trimBST(root->right, L + 1, R); return root; } else if (root->val == R) { root->right = NULL; root->left = trimBST(root->left, L, R - 1); return root; } else if (root->val<L)return trimBST(root->right, L, R); else if (root->val>R)return trimBST(root->left, L, R); else { root->left = trimBST(root->left, L, root->val - 1); root->right = trimBST(root->right, root->val + 1, R); return root; } }
[leetcode-669-Trim a Binary Search Tree]
标签：val etc tree should res amp col blog binary
原文地址：http://www.cnblogs.com/hellowooorld/p/7469224.html
