查找从一个节点到另一个节点的级别数

Question

我正在尝试编写一个函数，它将在四叉树中将一个节点的级别数返回到另一个节点。

这是我到目前为止所做的，但我确定这是不正确的，我只是想弄清楚原因：

int levels(QtreeNode * orig, QtreeNode * n) {

    //calculates the number of levels from orig to n
    if(orig==n)
        return 0;
    if(!orig->isLeaf())
        return 1 + levels(orig->nwChild, n) + levels(orig->neChild, n) + levels(orig->swChild, n)+ levels(orig->seChild, n);
    return 0;   

}

有什么想法吗？

Answer 1

你的错误是你在死路径的路径上添加了级别，但是你需要将这两个节点的方法联系起来

int levels(QtreeNode * orig, QtreeNode * n)
{
    int path;

    // found!
    if (orig == n)
        return 0;
    // it's dead end, do not calc that way
    if (orig->isLeaf())
        return -1;
    path = levels(orig->nwChild, n);
    // not dead end? it's fine, return that path
    if (path >= 0)
        return 1 + path;
    path = levels(orig->neChild, n);
    // not dead end? it's fine, return that path
    if (path >= 0)
        return 1 + path;
    path = levels(orig->swChild, n);
    // not dead end? it's fine, return that path
    if (path >= 0)
        return 1 + path;
    path = levels(orig->seChild, n);
    // not dead end? it's fine, return that path
    if (path >= 0)
        return 1 + path;
    // there is no path between this nodes
    return -2;
}