剑指Offer37 二叉树深度与平衡二叉树判断

 /*************************************************************************
     > File Name: 37_TreeDepth.cpp
     > Author: Juntaran
     > Mail: JuntaranMail@gmail.com
     > Created Time: 2016年09月03日 星期六 09时49分38秒
  ************************************************************************/

 #include <stdio.h>
 #include <malloc.h>
 #include <math.h>

 // 二叉树结构体
 struct BinaryTree
 {
     int val;
     struct BinaryTree* left;
     struct BinaryTree* right;
 };

 BinaryTree* createTree()
 {
     BinaryTree* root = (BinaryTree*)malloc(sizeof(BinaryTree));
     root->val = ;
     root->left = (BinaryTree*)malloc(sizeof(BinaryTree));
     root->left->val = ;
     root->right = (BinaryTree*)malloc(sizeof(BinaryTree));
     root->right->val = ;
     root->left->left = (BinaryTree*)malloc(sizeof(BinaryTree));
     root->left->left->val = ;
     root->left->left->left = NULL;
     root->left->left->right = NULL;
     root->left->right = (BinaryTree*)malloc(sizeof(BinaryTree));
     root->left->right->val = ;
     root->left->right->right = NULL;
     root->left->right->left = (BinaryTree*)malloc(sizeof(BinaryTree));
     root->left->right->left->val = ;
     root->left->right->left->left = NULL;
     root->left->right->left->right = NULL;
     root->right->right = (BinaryTree*)malloc(sizeof(BinaryTree));
     root->right->right->val = ;
     root->right->left = NULL;
     root->right->right->left = NULL;
     root->right->right->right = NULL;
     // root->right->right->right = (BinaryTree*)malloc(sizeof(BinaryTree));
     // root->right->right->right->val = 8;
     // root->right->right->right->left = root->right->right->right->right = NULL;

     return root;
 }

 // 二叉树中序遍历
 void InOrder(BinaryTree* root)
 {
     if (root == NULL)
         return;

     InOrder(root->left);
     printf("%d ", root->val);
     InOrder(root->right);
 }

 // 二叉树的深度
 int TreeDepth(BinaryTree* root)
 {
     if (root == NULL)
         return ;

     int left  = TreeDepth(root->left);
     int right = TreeDepth(root->right);

     return (left>right) ? (left+) : (right+);
 }

 // 判断一棵树是不是平衡二叉树
 bool isBalanced(BinaryTree* root)
 {
     if (root == NULL)
         return true;

     int left  = TreeDepth(root->left);
     int right = TreeDepth(root->right);

     int diff = abs(left - right);
     if (diff > )
         return false;

     return isBalanced(root->left) && isBalanced(root->right);
 }

 // 后序遍历方法
 bool isBalanced2(BinaryTree* root, int* depth)
 {
     if (root == NULL)
     {
         *depth = ;
         return true;
     }
     int left, right;
     if (isBalanced2(root->left, &left) && isBalanced2(root->right, &right))
     {
         int diff = abs(left - right);
         if (diff <= )
         {
             *depth =  + (left>right ? left : right);
             return true;
         }
     }
     return false;
 }

 bool isBalanced2(BinaryTree* root)
 {
     int depth = ;
     return isBalanced2(root, &depth);
 }

 int main()
 {
     BinaryTree* test = createTree();
     InOrder(test);
     int depth = TreeDepth(test);
     printf("\ndepth is %d\n", depth);
     if (isBalanced2(test) == true)
         printf("Balance\n");
     else
         printf("No Balance\n");

 }