-1
我很難理解這個代碼按大小對節點排序。 Rank返回小於密鑰的所有節點的大小。瞭解BST樹中的遞歸函數
http://algs4.cs.princeton.edu/32bst/BST.java.html
如何結果對於秩返回(鍵,x.left)???
代碼:
public int rank(Key key) {
return rank(key, root);
}
// Number of keys in the subtree less than key.
private int rank(Key key, Node x) {
if (x == null) return 0;
int cmp = key.compareTo(x.key);
if (cmp < 0) return rank(key, x.left);
else if (cmp > 0) return 1 + size(x.left) + rank(key, x.right);
else return size(x.left);
}
// is the symbol table empty?
public boolean isEmpty() {
return size() == 0;
}
// return number of key-value pairs in BST
public int size() {
return size(root);
}
// return number of key-value pairs in BST rooted at x
private int size(Node x) {
if (x == null) return 0;
else return x.N;
}