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feat: add solutions to lc problem: No.0110. Balanced Binary Tree
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‎solution/0100-0199/0110.Balanced Binary Tree/README.md

+85-2
Original file line numberDiff line numberDiff line change
@@ -46,7 +46,6 @@
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<li><code>-10<sup>4</sup> <= Node.val <= 10<sup>4</sup></code></li>
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</ul>
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## 解法
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<!-- 这里可写通用的实现逻辑 -->
@@ -58,15 +57,99 @@
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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```python
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60+
# Definition for a binary tree node.
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# class TreeNode:
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# def __init__(self, val=0, left=None, right=None):
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# self.val = val
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# self.left = left
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# self.right = right
66+
class Solution:
67+
def isBalanced(self, root: TreeNode) -> bool:
68+
def height(root):
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if not root:
70+
return 0
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return 1 + max(height(root.left), height(root.right))
72+
if not root:
73+
return True
74+
left_height, right_height = height(root.left), height(root.right)
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return abs(left_height - right_height) <= 1 and self.isBalanced(root.left) and self.isBalanced(root.right)
6276
```
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### **Java**
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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```java
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/**
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* Definition for a binary tree node.
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* public class TreeNode {
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* int val;
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* TreeNode left;
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* TreeNode right;
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* TreeNode() {}
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* TreeNode(int val) { this.val = val; }
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* TreeNode(int val, TreeNode left, TreeNode right) {
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* this.val = val;
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* this.left = left;
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* this.right = right;
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* }
96+
* }
97+
*/
98+
class Solution {
99+
public boolean isBalanced(TreeNode root) {
100+
if (root == null) {
101+
return true;
102+
}
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int leftHeight = height(root.left);
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int rightHeight = height(root.right);
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return Math.abs(leftHeight - rightHeight) <= 1 && isBalanced(root.left) && isBalanced(root.right);
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}
107+
108+
private int height(TreeNode root) {
109+
if (root == null) {
110+
return 0;
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}
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int l = height(root.left);
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int r = height(root.right);
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return 1 + Math.max(l, r);
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}
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}
117+
```
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119+
### **C++**
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```cpp
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/**
123+
* Definition for a binary tree node.
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* struct TreeNode {
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* int val;
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* TreeNode *left;
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* TreeNode *right;
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* TreeNode() : val(0), left(nullptr), right(nullptr) {}
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* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
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* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
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* };
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*/
133+
class Solution {
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public:
135+
bool isBalanced(TreeNode* root) {
136+
if (root == nullptr) {
137+
return true;
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}
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int leftHeight = height(root->left);
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int rightHeight = height(root->right);
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return abs(leftHeight - rightHeight) <= 1 && isBalanced(root->left) && isBalanced(root->right);
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}
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private:
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int height(TreeNode* root) {
145+
if (root == nullptr) {
146+
return 0;
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}
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int l = height(root->left);
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int r = height(root->right);
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return 1 + max(l, r);
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}
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};
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```
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### **...**

‎solution/0100-0199/0110.Balanced Binary Tree/README_EN.md

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Original file line numberDiff line numberDiff line change
@@ -42,21 +42,104 @@
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<li><code>-10<sup>4</sup> &lt;= Node.val &lt;= 10<sup>4</sup></code></li>
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</ul>
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## Solutions
4746

4847
<!-- tabs:start -->
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5049
### **Python3**
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```python
53-
52+
# Definition for a binary tree node.
53+
# class TreeNode:
54+
# def __init__(self, val=0, left=None, right=None):
55+
# self.val = val
56+
# self.left = left
57+
# self.right = right
58+
class Solution:
59+
def isBalanced(self, root: TreeNode) -> bool:
60+
def height(root):
61+
if not root:
62+
return 0
63+
return 1 + max(height(root.left), height(root.right))
64+
if not root:
65+
return True
66+
left_height, right_height = height(root.left), height(root.right)
67+
return abs(left_height - right_height) <= 1 and self.isBalanced(root.left) and self.isBalanced(root.right)
5468
```
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5670
### **Java**
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```java
73+
/**
74+
* Definition for a binary tree node.
75+
* public class TreeNode {
76+
* int val;
77+
* TreeNode left;
78+
* TreeNode right;
79+
* TreeNode() {}
80+
* TreeNode(int val) { this.val = val; }
81+
* TreeNode(int val, TreeNode left, TreeNode right) {
82+
* this.val = val;
83+
* this.left = left;
84+
* this.right = right;
85+
* }
86+
* }
87+
*/
88+
class Solution {
89+
public boolean isBalanced(TreeNode root) {
90+
if (root == null) {
91+
return true;
92+
}
93+
int leftHeight = height(root.left);
94+
int rightHeight = height(root.right);
95+
return Math.abs(leftHeight - rightHeight) <= 1 && isBalanced(root.left) && isBalanced(root.right);
96+
}
97+
98+
private int height(TreeNode root) {
99+
if (root == null) {
100+
return 0;
101+
}
102+
int l = height(root.left);
103+
int r = height(root.right);
104+
return 1 + Math.max(l, r);
105+
}
106+
}
107+
```
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109+
### **C++**
110+
111+
```cpp
112+
/**
113+
* Definition for a binary tree node.
114+
* struct TreeNode {
115+
* int val;
116+
* TreeNode *left;
117+
* TreeNode *right;
118+
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
119+
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
120+
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
121+
* };
122+
*/
123+
class Solution {
124+
public:
125+
bool isBalanced(TreeNode* root) {
126+
if (root == nullptr) {
127+
return true;
128+
}
129+
int leftHeight = height(root->left);
130+
int rightHeight = height(root->right);
131+
return abs(leftHeight - rightHeight) <= 1 && isBalanced(root->left) && isBalanced(root->right);
132+
}
133+
private:
134+
int height(TreeNode* root) {
135+
if (root == nullptr) {
136+
return 0;
137+
}
138+
int l = height(root->left);
139+
int r = height(root->right);
140+
return 1 + max(l, r);
141+
}
142+
};
60143
```
61144
62145
### **...**

‎solution/0100-0199/0110.Balanced Binary Tree/Solution.cpp

+24-7
Original file line numberDiff line numberDiff line change
@@ -1,14 +1,31 @@
1+
/**
2+
* Definition for a binary tree node.
3+
* struct TreeNode {
4+
* int val;
5+
* TreeNode *left;
6+
* TreeNode *right;
7+
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
8+
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
9+
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
10+
* };
11+
*/
112
class Solution {
213
public:
314
bool isBalanced(TreeNode* root) {
4-
if (!root) return true;
5-
if (abs(getDepth(root->left) - getDepth(root->right)) > 1) return false;
6-
return isBalanced(root->left) && isBalanced(root->right);
15+
if (root == nullptr) {
16+
return true;
17+
}
18+
int leftHeight = height(root->left);
19+
int rightHeight = height(root->right);
20+
return abs(leftHeight - rightHeight) <= 1 && isBalanced(root->left) && isBalanced(root->right);
721
}
8-
922
private:
10-
int getDepth(TreeNode *root) {
11-
if (!root) return 0;
12-
return 1 + max(getDepth(root->left), getDepth(root->right));
23+
int height(TreeNode* root) {
24+
if (root == nullptr) {
25+
return 0;
26+
}
27+
int l = height(root->left);
28+
int r = height(root->right);
29+
return 1 + max(l, r);
1330
}
1431
};

‎solution/0100-0199/0110.Balanced Binary Tree/Solution.java

+29-8
Original file line numberDiff line numberDiff line change
@@ -1,13 +1,34 @@
1+
/**
2+
* Definition for a binary tree node.
3+
* public class TreeNode {
4+
* int val;
5+
* TreeNode left;
6+
* TreeNode right;
7+
* TreeNode() {}
8+
* TreeNode(int val) { this.val = val; }
9+
* TreeNode(int val, TreeNode left, TreeNode right) {
10+
* this.val = val;
11+
* this.left = left;
12+
* this.right = right;
13+
* }
14+
* }
15+
*/
116
class Solution {
217
public boolean isBalanced(TreeNode root) {
3-
return depth(root) != -1;
18+
if (root == null) {
19+
return true;
20+
}
21+
int leftHeight = height(root.left);
22+
int rightHeight = height(root.right);
23+
return Math.abs(leftHeight - rightHeight) <= 1 && isBalanced(root.left) && isBalanced(root.right);
424
}
5-
private int depth(TreeNode root) {
6-
if (root == null) return 0;
7-
int left = depth(root.left);
8-
if (left == -1) return -1;
9-
int right = depth(root.right);
10-
if (right == -1 || Math.abs(left - right) > 1) return -1;
11-
return Math.max(left, right) + 1;
25+
26+
private int height(TreeNode root) {
27+
if (root == null) {
28+
return 0;
29+
}
30+
int l = height(root.left);
31+
int r = height(root.right);
32+
return 1 + Math.max(l, r);
1233
}
1334
}

‎solution/0100-0199/0110.Balanced Binary Tree/Solution.py

+16
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,16 @@
1+
# Definition for a binary tree node.
2+
# class TreeNode:
3+
# def __init__(self, val=0, left=None, right=None):
4+
# self.val = val
5+
# self.left = left
6+
# self.right = right
7+
class Solution:
8+
def isBalanced(self, root: TreeNode) -> bool:
9+
def height(root):
10+
if not root:
11+
return 0
12+
return 1 + max(height(root.left), height(root.right))
13+
if not root:
14+
return True
15+
left_height, right_height = height(root.left), height(root.right)
16+
return abs(left_height - right_height) <= 1 and self.isBalanced(root.left) and self.isBalanced(root.right)

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