（015）实现一个函数检查一棵树是否平衡（keep it up）

int MinDepth = std::numeric_limits<int>::max();
int MaxDepth = std::numeric_limits<int>::min();

struct TreeNode
{
int data;
TreeNode* child;
TreeNode* brother;
};

bool isBlanceTree(const TreeNode* vNode, int vDepth=0)
{
if (vNode == NULL)
{
if (vDepth == 0) return true;

if (vDepth < MinDepth)
{
MinDepth = vDepth;
}

if (vDepth > MaxDepth)
{
MaxDepth = vDepth;
}

if (MaxDepth - MinDepth > 1) return false;
return true;
}

bool IsBlance = true;
if (vNode->child != NULL)
{
IsBlance = isBlanceTree(vNode->child, vDepth+1);
}

if (IsBlance && vNode->brother != NULL)
{
IsBlance = isBlanceTree(vNode->brother, vDepth);
}

return IsBlance;
}