bool isBalanced(TreeNode *root) {
bool balancedFlag = true;
isBalancedTree(root, balancedFlag);
return balancedFlag;
}
/***判断二叉树是否为平衡二叉树***/
int isBalancedTree(BitTree* T, int* depth)
{
int left, right;
if(T == NULL)
{
*depth = 0;
return 1;
}
if(isBalancedTree(T->lchild, &left) && isBalancedTree(T->rchild, &right))
{
int diff = left - right;
if(diff >= -1 && diff <= 1)
{
*depth = (left > right)?(left + 1):(right + 1);
return 1;
}
}
return 0;
}
bool isBalancedTree(TreeNode* root,int& height)
{
if(root == nullptr)
{
height = 0;
return true;
}
int leftHeight,rightHeight;
bool isLeft = isBalancedTree(root->left,leftHeight);
bool isRight = isBalancedTree(root->right,rightHeight);
height = max(leftHeight,rightHeight)+1;
if(isLeft && isRight && abs(leftHeight-rightHeight)<=1)
{
return true;
}
else
return false;
}
int isBalancedTree(TreeNode *root, bool &balancedFlag) {
if (root == nullptr) {
return 0;
} else {
if (balancedFlag) {
int leftHeight = isBalancedTree(root->left, balancedFlag);
int rightHeight = isBalancedTree(root->right, balancedFlag);
if (balancedFlag) {
if (leftHeight > rightHeight) {
balancedFlag = ((leftHeight - rightHeight) <= 1);
} else {
balancedFlag = ((rightHeight - leftHeight) <= 1);
}
}
return (1 + std::max(leftHeight, rightHeight));
} else {
return 0;
}
}
}
bool isBalanced(TreeNode* root)
{
int i = 0;
return isBalancedTree(root,i);
}
