Fix splay tree code.

diff --git a/lib/splay_tree.c b/lib/splay_tree.c
index 1b320cc..32e99b4 100644 (file)
--- a/lib/splay_tree.c
+++ b/lib/splay_tree.c
@@ -28,194 +28,206 @@
 
 static splay_node_t *splay_top_down(splay_tree_t *tree, const void *data, int *result) {
        splay_node_t left = {0}, right = {0};
-       splay_node_t *leftbottom = &left, *rightbottom = &right, *child;
-       splay_node_t *node = tree->root;
+       splay_node_t *leftbottom = &left, *rightbottom = &right, *child, *grandchild;
+       splay_node_t *root = tree->root;
        int c;
 
-       while((c = tree->compare(data, node->data))) {
-               if(c < 0) {
-                       child = node->left;
+       if(!root) {
+               if(result)
+                       *result = 0;
+               return NULL;
+       }
+
+       while((c = tree->compare(data, root->data))) {
+               if(c < 0 && (child = root->left)) {
+                       c = tree->compare(data, child->data);
 
-                       if(child) {
-                               c = tree->compare(data, child->data);
+                       if(c < 0 && (grandchild = child->left)) {
+                               rightbottom->left = child;
+                               child->parent = rightbottom;
+                               rightbottom = child;
                                
-                               if(c < 0) {
-                                       rightbottom->left = child;
-                                       child->parent = rightbottom;
-                                       rightbottom = child;
-
-                                       node->left = child->right;
-                                       child->right = node;
-                                       node->parent = child;
-                                       node = child->left;
-                                       child->left = NULL;
-                               } else if (c > 0) {
-                                       if(!child->right)
-                                               break;
-
-                                       leftbottom->right = child;
-                                       child->parent = leftbottom;
-                                       leftbottom = child;
-
-                                       rightbottom->left = node;
-                                       node->parent = rightbottom;
-                                       rightbottom = node;
-
-                                       node->left = NULL;
-                                       node = child->right;
-                                       child->right = NULL;
-                               } else {
-                                       rightbottom->left = node;
-                                       node->parent = rightbottom;
-                                       rightbottom = node;
-
-                                       node->left = NULL;
-                                       child->parent = NULL;
-                                       node = child;
-                                       break;
-                               }
+                               if((root->left = child->right))
+                                       child->right->parent = root;
+                               
+                               child->right = root;
+                               root->parent = child;
+
+                               child->left = NULL;
+                               grandchild->parent = NULL;
+
+                               root = grandchild;
+                       } else if (c > 0 && (grandchild = child->right)) {
+                               leftbottom->right = child;
+                               child->parent = leftbottom;
+                               leftbottom = child;
+
+                               child->right = NULL;
+                               grandchild->parent = NULL;
+
+                               rightbottom->left = root;
+                               root->parent = rightbottom;
+                               rightbottom = root;
+
+                               root->left = NULL;
+
+                               root = grandchild;
                        } else {
+                               rightbottom->left = root;
+                               root->parent = rightbottom;
+                               rightbottom = root;
+                               
+                               root->left = NULL;
+                               child->parent = NULL;
+
+                               root = child;
                                break;
                        }
-               } else {
-                       child = node->right;
+               } else if(c > 0 && (child = root->right)) {
+                       c = tree->compare(data, child->data);
 
-                       if(child) {
-                               c = tree->compare(data, child->data);
+                       if(c > 0 && (grandchild = child->right)) {
+                               leftbottom->right = child;
+                               child->parent = leftbottom;
+                               leftbottom = child;
+                               
+                               if((root->right = child->left))
+                                       child->left->parent = root;
                                
-                               if(c > 0) {
-                                       leftbottom->right = child;
-                                       child->parent = leftbottom;
-                                       leftbottom = child;
-
-                                       node->right = child->left;
-                                       child->left = node;
-                                       node->parent = child;
-                                       node = child->right;
-                                       child->right = NULL;
-                               } else if (c < 0) {
-                                       if(!child->left)
-                                               break;
-
-                                       rightbottom->left = child;
-                                       child->parent = rightbottom;
-                                       rightbottom = child;
-
-                                       leftbottom->right = node;
-                                       node->parent = leftbottom;
-                                       leftbottom = node;
-
-                                       node->right = NULL;
-                                       node = child->left;
-                                       child->left = NULL;
-                               } else {
-                                       leftbottom->right = node;
-                                       node->parent = leftbottom;
-                                       leftbottom = node;
-
-                                       node->right = NULL;
-                                       child->parent = NULL;
-                                       node = child;
-                                       break;
-                               }
+                               child->left = root;
+                               root->parent = child;
+
+                               child->right = NULL;
+                               grandchild->parent = NULL;
+
+                               root = grandchild;
+                       } else if (c < 0 && (grandchild = child->left)) {
+                               rightbottom->left = child;
+                               child->parent = rightbottom;
+                               rightbottom = child;
+
+                               child->left = NULL;
+                               grandchild->parent = NULL;
+
+                               leftbottom->right = root;
+                               root->parent = leftbottom;
+                               leftbottom = root;
+
+                               root->right = NULL;
+
+                               root = grandchild;
                        } else {
+                               leftbottom->right = root;
+                               root->parent = leftbottom;
+                               leftbottom = root;
+
+                               root->right = NULL;
+                               child->parent = NULL;
+
+                               root = child;
                                break;
                        }
+               } else {
+                       break;
                }
        }
 
-       tree->root = node;
-
        /* Merge trees */
 
        if(left.right) {
-               if(node->left) {
-                       leftbottom->right = node->left;
-                       node->left->parent = leftbottom;
+               if(root->left) {
+                       leftbottom->right = root->left;
+                       root->left->parent = leftbottom;
                }
-               node->left = left.right;
-               left.right->parent = node;
+               root->left = left.right;
+               left.right->parent = root;
        }
 
        if(right.left) {
-               if(node->right) {
-                       rightbottom->left = node->right;
-                       node->right->parent = rightbottom;
+               if(root->right) {
+                       rightbottom->left = root->right;
+                       root->right->parent = rightbottom;
                }
-               node->right = right.left;
-               right.left->parent = node;
+               root->right = right.left;
+               right.left->parent = root;
        }
 
+       /* Return result */
+
+       tree->root = root;
        if(result)
                *result = c;
 
-       return node;
+       return tree->root;
 }
-                               
-               
+                       
 static void splay_bottom_up(splay_tree_t *tree, splay_node_t *node) {
-       splay_node_t *parent, *grandparent;
-
-       while(node->parent) {
-               parent = node->parent;
-               grandparent = node->parent->parent;
+       splay_node_t *parent, *grandparent, *greatgrandparent;
 
-               if(!grandparent) { /* zig */
+       while((parent = node->parent)) {
+               if(!(grandparent = parent->parent)) { /* zig */
                        if(node == parent->left) {
-                               parent->left = node->right;
+                               if((parent->left = node->right))                                
+                                       parent->left->parent = parent;
                                node->right = parent;
                        } else {
-                               parent->right = node->left;
+                               if((parent->right = node->left))
+                                       parent->right->parent = parent;
                                node->left = parent;
                        }
 
                        parent->parent = node;
                        node->parent = NULL;
                } else {
-                       if(node == grandparent->left->left) { /* left zig-zig */
-                               grandparent->left = parent->right;
+                       greatgrandparent = grandparent->parent;
+
+                       if(node == parent->left && parent == grandparent->left) { /* left zig-zig */
+                               if((grandparent->left = parent->right))
+                                       grandparent->left->parent = grandparent;
                                parent->right = grandparent;
                                grandparent->parent = parent;
 
-                               parent->left = node->right;
+                               if((parent->left = node->right))
+                                       parent->left->parent = parent;
                                node->right = parent;
                                parent->parent = node;
-
-                       } else if(node == grandparent->right->right) { /* right zig-zig */
-                               grandparent->right = parent->left;
+                       } else if(node == parent->right && parent == grandparent->right) { /* right zig-zig */
+                               if((grandparent->right = parent->left))
+                                       grandparent->right->parent = grandparent;
                                parent->left = grandparent;
                                grandparent->parent = parent;
 
-                               parent->right = node->left;
+                               if((parent->right = node->left))
+                                       parent->right->parent = parent;
                                node->left = parent;
                                parent->parent = node;
-
-                       } else if(node == grandparent->left->right) { /* left-right zig-zag */
-                               parent->right = node->left;
+                       } else if(node == parent->right && parent == grandparent->left) { /* left-right zig-zag */
+                               if((parent->right = node->left))
+                                       parent->right->parent = parent;
                                node->left = parent;
                                parent->parent = node;
 
-                               grandparent->left = node->right;
+                               if((grandparent->left = node->right))
+                                       grandparent->left->parent = grandparent;
                                node->right = grandparent;
                                grandparent->parent = node;
-
                        } else { /* right-left zig-zag */
-                               parent->left = node->right;
+                               if((parent->left = node->right))
+                                       parent->left->parent = parent;
                                node->right = parent;
                                parent->parent = node;
 
-                               grandparent->right = node->left;
+                               if((grandparent->right = node->left))
+                                       grandparent->right->parent = grandparent;
                                node->left = grandparent;
                                grandparent->parent = node;
                        }
 
-                       node->parent = grandparent->parent;
-
-                       if(node->parent) {
-                               if(grandparent == node->parent->left)
-                                       node->parent->left = node;
+                       if((node->parent = greatgrandparent)) {
+                               if(grandparent == greatgrandparent->left)
+                                       greatgrandparent->left = node;
                                else
-                                       node->parent->right = node;
+                                       greatgrandparent->right = node;
                        }
                }
        }
@@ -311,26 +323,20 @@ splay_node_t *splay_search_closest_node_nosplay(const splay_tree_t *tree, const
                if(c < 0) {
                        if(node->left)
                                node = node->left;
-                       else {
-                               if(result)
-                                       *result = -1;
+                       else
                                break;
-                       }
                } else if(c > 0) {
                        if(node->right)
                                node = node->right;
-                       else {
-                               if(result)
-                                       *result = 1;
+                       else 
                                break;
-                       }
                } else {
-                       if(result)
-                               *result = 0;
                        break;
                }
        }
 
+       if(result)
+               *result = c;
        return node;
 }
 
@@ -506,9 +512,11 @@ void splay_unlink_node(splay_tree_t *tree, splay_node_t *node) {
                        node->prev->right = node->right;
                        node->right->parent = node->prev;
                }
-       } else {
+       } else if(node->right) {
                node->right->parent = NULL;
                tree->root = node->right;
+       } else {
+               tree->root = NULL;
        }
 }