每日一题——求二叉树的高度，销毁二叉树

1，求二叉树的最大高度：

int length(Node* root)
{
    if(root == NULL)
        return 0;

    int leftLength = length(root->left);
    int rightLength = length(root->right);

    return (leftLength>=rightLength?(leftLength+1):(rightLength+1));
}

2，二叉树的最小高度：根节点到叶子节点的最短距离

int length(Node* root)
{
    if(root == NULL)
        return 0;
    int leftLength = length(root->left);
    int rightLength = length(root->right);
    if(leftLength == 0 && rightLength == 0)
        return leftLength+1;
    if(leftLength == 0 && rightLength != 0)
        return rightLength+1;
    if(leftLength != 0 && rightLength == 0)
        return leftLength+1;
    if(leftLength != 0 && rightLength != 0)
        return ((leftLength>=rightLength)?(leftLength+1):(rightLength+1));
}

3,销毁二叉树：

void Destory(Node* root)
{
    Destory(root->left);
    Destory(root->right);
    delete root;
    root = NULL;
}