docs: add code that question is based on

1 files changed, 45 insertions, 0 deletions

diff --git a/src/03/06/README.md b/src/03/06/README.md
index 123d921..01a4dbe 100644
--- a/src/03/06/README.md
+++ b/src/03/06/README.md
@@ -1,3 +1,48 @@
 Why does the method `remove(x)` in the `RedBlackTree` implementation
 perform the assignment `u:parent = w:parent?`
 Shouldn’t this already be done by the call to `splice(w)`?
+
+```java
+boolean remove(T x)
+{
+  Node<T> u = findLast(x);
+  if (u == nil || compare(u.x, x) != 0)
+    return false;
+  Node<T> w = u.right;
+  if (w == nil) {
+    w = u;
+    u = w.left;
+  } else {
+    while (w.left != nil)
+      w = w.left;
+    u.x = w.x;
+    u = w.right;
+  }
+  splice(w);
+  u.colour += w.colour;
+  u.parent = w.parent;
+  removeFixup(u);
+  return true;
+}
+
+void removeFixup(Node<T> u) {
+  while (u.colour > black) {
+    if (u == r) {
+      u.colour = black;
+    } else if (u.parent.left.colour == red) {
+      u = removeFixupCase1(u);
+    } else if (u == u.parent.left) {
+      u = removeFixupCase2(u);
+    } else {
+      u = removeFixupCase3(u);
+    }
+  }
+  if (u != r) {
+    Node<T> w = u.parent;
+    if (w.right.colour == red && w.left.colour == black) {
+      flipLeft(w);
+    }
+  }
+}
+```
+Source [Open Data Structures](https://www.aupress.ca/app/uploads/120226_99Z_Morin_2013-Open_Data_Structures.pdf)