refactor node insertion recoloring code

diff --git a/source/rbt/rbt.c b/source/rbt/rbt.c
index 2235add7a559f2e6e393c81c3ed8a7d038b7935a..9cc96a43cf5137419a3430ea4641ca389c6a4938 100644 (file)
--- a/source/rbt/rbt.c
+++ b/source/rbt/rbt.c
@@ -91,22 +91,14 @@ static void rbt_ins_recolor(rbt_t* tree, rbt_node_t* node){
                parent->color = BLACK;
                uncle->color = BLACK;
                rbt_ins_recolor(tree, grandparent);
-       }else if(node == parent->right && parent == grandparent->left){
-               //parent is red, uncle is black, "inside left" case
-               //first rotate node and parent : transform to "outside" case
-               rotate(tree, parent, LEFT);
-               rbt_ins_rebalance(tree, parent, LEFT);
-       }else if(node == parent->left && parent == grandparent->right){
-               //parent is red, uncle is black, "inside right" case
-               //first rotate node and parent : transform to "outside" case
-               rotate(tree, parent, RIGHT);
-               rbt_ins_rebalance(tree, parent, RIGHT);
-       }else if(node == parent->left && parent == grandparent->left){
-               //parent is red, uncle is black, "outside left" case
-               rbt_ins_rebalance(tree, node , LEFT);
-       }else if(node == parent->right && parent == grandparent->right){
-               //parent is red, uncle is black, "outside right" case
-               rbt_ins_rebalance(tree, node, RIGHT);
+       }else{
+               direction_t node_side = (node == parent->left ? LEFT : RIGHT);
+               direction_t parent_side = (parent == grandparent->left ? LEFT : RIGHT);
+               if(node_side != parent_side){ // "inside" case
+                       rotate(tree, parent, parent_side); //transform to "outside" case
+                       node = parent; //parent now lowest node.
+               }
+               rbt_ins_rebalance(tree, node, parent_side);
        }
 }
 
@@ -114,7 +106,6 @@ static void rbt_insert_node(rbt_t* tree, rbt_node_t* node, rbt_node_t* parent){
        if(NULL == parent){ /* inserting root of the tree */
                tree->root = node;
                rbt_ins_recolor(tree, node);
-       //}else if(node->contents < parent->contents){
        }else if(tree->comp(node->contents, parent->contents) < 0){
                if(parent->left){
                        rbt_insert_node(tree, node, parent->left);