1 /*************************************************************************
2 > File Name: 37_TreeDepth.cpp
3 > Author: Juntaran
4 > Mail: JuntaranMail@gmail.com
5 > Created Time: 2016年09月03日 星期六 09时49分38秒
6 ************************************************************************/
7
8 #include <stdio.h>
9 #include <malloc.h>
10 #include <math.h>
11
12 // 二叉树结构体
13 struct BinaryTree
14 {
15 int val;
16 struct BinaryTree* left;
17 struct BinaryTree* right;
18 };
19
20 BinaryTree* createTree()
21 {
22 BinaryTree* root = (BinaryTree*)malloc(sizeof(BinaryTree));
23 root->val = 1;
24 root->left = (BinaryTree*)malloc(sizeof(BinaryTree));
25 root->left->val = 2;
26 root->right = (BinaryTree*)malloc(sizeof(BinaryTree));
27 root->right->val = 3;
28 root->left->left = (BinaryTree*)malloc(sizeof(BinaryTree));
29 root->left->left->val = 4;
30 root->left->left->left = NULL;
31 root->left->left->right = NULL;
32 root->left->right = (BinaryTree*)malloc(sizeof(BinaryTree));
33 root->left->right->val = 5;
34 root->left->right->right = NULL;
35 root->left->right->left = (BinaryTree*)malloc(sizeof(BinaryTree));
36 root->left->right->left->val = 7;
37 root->left->right->left->left = NULL;
38 root->left->right->left->right = NULL;
39 root->right->right = (BinaryTree*)malloc(sizeof(BinaryTree));
40 root->right->right->val = 6;
41 root->right->left = NULL;
42 root->right->right->left = NULL;
43 root->right->right->right = NULL;
44 // root->right->right->right = (BinaryTree*)malloc(sizeof(BinaryTree));
45 // root->right->right->right->val = 8;
46 // root->right->right->right->left = root->right->right->right->right = NULL;
47
48 return root;
49 }
50
51 // 二叉树中序遍历
52 void InOrder(BinaryTree* root)
53 {
54 if (root == NULL)
55 return;
56
57 InOrder(root->left);
58 printf("%d ", root->val);
59 InOrder(root->right);
60 }
61
62 // 二叉树的深度
63 int TreeDepth(BinaryTree* root)
64 {
65 if (root == NULL)
66 return 0;
67
68 int left = TreeDepth(root->left);
69 int right = TreeDepth(root->right);
70
71 return (left>right) ? (left+1) : (right+1);
72 }
73
74 // 判断一棵树是不是平衡二叉树
75 bool isBalanced(BinaryTree* root)
76 {
77 if (root == NULL)
78 return true;
79
80 int left = TreeDepth(root->left);
81 int right = TreeDepth(root->right);
82
83 int diff = abs(left - right);
84 if (diff > 1)
85 return false;
86
87 return isBalanced(root->left) && isBalanced(root->right);
88 }
89
90 // 后序遍历方法
91 bool isBalanced2(BinaryTree* root, int* depth)
92 {
93 if (root == NULL)
94 {
95 *depth = 0;
96 return true;
97 }
98 int left, right;
99 if (isBalanced2(root->left, &left) && isBalanced2(root->right, &right))
100 {
101 int diff = abs(left - right);
102 if (diff <= 1)
103 {
104 *depth = 1 + (left>right ? left : right);
105 return true;
106 }
107 }
108 return false;
109 }
110
111 bool isBalanced2(BinaryTree* root)
112 {
113 int depth = 0;
114 return isBalanced2(root, &depth);
115 }
116
117
118
119 int main()
120 {
121 BinaryTree* test = createTree();
122 InOrder(test);
123 int depth = TreeDepth(test);
124 printf("\ndepth is %d\n", depth);
125 if (isBalanced2(test) == true)
126 printf("Balance\n");
127 else
128 printf("No Balance\n");
129
130 }
