From 63a9066c6cdd10751ba5e9142fc3341f50392688 Mon Sep 17 00:00:00 2001
From: kim <kim@3cdefd35-fc62-479d-8e8d-bae585ffb9ca>
Date: Thu, 16 Apr 2009 00:44:32 +0000
Subject: [PATCH] Added IsFirstChild and LastChild

git-svn-id: svn+ssh://idea.nguyen.vg/svn/sxsi/trunk/XMLTree@311 3cdefd35-fc62-479d-8e8d-bae585ffb9ca
---
 XMLTree.cpp | 12 +++++++++++-
 XMLTree.h   |  8 ++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/XMLTree.cpp b/XMLTree.cpp
index 99d0395..249143c 100644
--- a/XMLTree.cpp
+++ b/XMLTree.cpp
@@ -357,7 +357,9 @@ bool XMLTree::IsChild(treeNode x, treeNode y)
     if (!is_ancestor(Par, x, y)) return false;
     return depth(Par, x) == (depth(Par, y) + 1);
  }
-
+bool XMLTree::IsFirstChild(treeNode x){
+  return ((x != NULLT)&&(x==Root() || prev_sibling(Par,x) == NULLT));
+}
 // NumChildren(x): number of children of node x. Constant time with the data structure
 // of Sadakane.
 int XMLTree::NumChildren(treeNode x) 
@@ -499,6 +501,14 @@ treeNode XMLTree::FirstChild(treeNode x)
     return first_child(Par, x);
  }
 
+treeNode XMLTree::LastChild(treeNode x) 
+{
+  if (x == Root() || isleaf(Par,x) || x == NULLT)
+    return x;
+  else
+  return find_open(Par,find_close(Par,parent(Par,x))-1);
+}
+
 // NextSibling(x): returns the next sibling of node x, assuming it exists.
 treeNode XMLTree::NextSibling(treeNode x) 
  {
diff --git a/XMLTree.h b/XMLTree.h
index 9b79ae3..1268cb6 100644
--- a/XMLTree.h
+++ b/XMLTree.h
@@ -153,6 +153,9 @@ public:
   
    /** IsChild(x,y): returns whether node x is parent of node y. */
    bool IsChild(treeNode x, treeNode y);
+
+   /** IsChild(x,y): returns whether node x is the first child of its parent */
+   bool IsFirstChild(treeNode x);
    
    /** NumChildren(x): number of children of node x. Constant time with the 
     * data structure of Sadakane. */
@@ -191,8 +194,13 @@ public:
     * Very fast in BP. */
    treeNode FirstChild(treeNode x);
    
+   /** LastChild(x): returns the last child of node x. 
+    * Implemented by Kim naively. */
+   treeNode LastChild(treeNode x);
+
    /** NextSibling(x): returns the next sibling of node x, assuming it 
     * exists. */
+
    treeNode NextSibling(treeNode x);
    
    /** PrevSibling(x): returns the previous sibling of node x, assuming it 
-- 
2.17.1