From 193fc4b454135d67d331afcebc7f956a62ab08fb Mon Sep 17 00:00:00 2001 From: Chewing_Bever Date: Sun, 29 Jan 2023 20:33:11 +0100 Subject: [PATCH] refactor(tree): store children as static array instead --- src/tree/vieter_tree.c | 10 +++--- src/tree/vieter_tree_balancing.c | 56 ++++++++++++++++---------------- src/tree/vieter_tree_node.c | 45 +++++++++---------------- src/tree/vieter_tree_node.h | 8 +++-- 4 files changed, 54 insertions(+), 65 deletions(-) diff --git a/src/tree/vieter_tree.c b/src/tree/vieter_tree.c index bd0200e..92f8831 100644 --- a/src/tree/vieter_tree.c +++ b/src/tree/vieter_tree.c @@ -80,13 +80,13 @@ void vieter_tree_free(vieter_tree *tree) { stack = realloc(stack, capacity * sizeof(vieter_tree_node *)); } - if (node->left != NULL) { - stack[size] = node->left; + if (node->children[0] != NULL) { + stack[size] = node->children[0]; size++; } - if (node->right != NULL) { - stack[size] = node->right; + if (node->children[1] != NULL) { + stack[size] = node->children[1]; size++; } @@ -113,7 +113,7 @@ bool vieter_tree_validate(vieter_tree *tree) { expected_black_nodes++; } - node = node->left; + node = node->children[0]; } return vieter_tree_node_get(tree->root, vieter_tree_node_black) && diff --git a/src/tree/vieter_tree_balancing.c b/src/tree/vieter_tree_balancing.c index d9fc66e..c04825d 100644 --- a/src/tree/vieter_tree_balancing.c +++ b/src/tree/vieter_tree_balancing.c @@ -16,15 +16,15 @@ bool vieter_tree_node_validate(vieter_tree_node *node, // black. bool correctly_colored_children = vieter_tree_node_get(node, vieter_tree_node_black) || - ((node->left == NULL || - vieter_tree_node_get(node->left, vieter_tree_node_black)) && - (node->right == NULL || - vieter_tree_node_get(node->right, vieter_tree_node_black))); + ((node->children[0] == NULL || + vieter_tree_node_get(node->children[0], vieter_tree_node_black)) && + (node->children[1] == NULL || + vieter_tree_node_get(node->children[1], vieter_tree_node_black))); return correctly_colored_children && - vieter_tree_node_validate(node->left, passed_black_nodes, + vieter_tree_node_validate(node->children[0], passed_black_nodes, expected_black_nodes) && - vieter_tree_node_validate(node->right, passed_black_nodes, + vieter_tree_node_validate(node->children[1], passed_black_nodes, expected_black_nodes); } @@ -48,10 +48,10 @@ vieter_tree_node *vieter_tree_node_balance(vieter_tree_node *node) { left = node; right = parent; - children[0] = node->left; - children[1] = node->right; - children[2] = parent->right; - children[3] = grand_parent->right; + children[0] = node->children[0]; + children[1] = node->children[1]; + children[2] = parent->children[1]; + children[3] = grand_parent->children[1]; } else if (node->key < parent->key && parent->key > grand_parent->key) { root->key = node->key; root->data = node->data; @@ -62,10 +62,10 @@ vieter_tree_node *vieter_tree_node_balance(vieter_tree_node *node) { left = node; right = parent; - children[0] = grand_parent->left; - children[1] = node->left; - children[2] = node->right; - children[3] = parent->right; + children[0] = grand_parent->children[0]; + children[1] = node->children[0]; + children[2] = node->children[1]; + children[3] = parent->children[1]; } else if (node->key > parent->key && parent->key < grand_parent->key) { root->key = node->key; root->data = node->data; @@ -76,10 +76,10 @@ vieter_tree_node *vieter_tree_node_balance(vieter_tree_node *node) { left = parent; right = node; - children[0] = parent->left; - children[1] = node->left; - children[2] = node->right; - children[3] = grand_parent->right; + children[0] = parent->children[0]; + children[1] = node->children[0]; + children[2] = node->children[1]; + children[3] = grand_parent->children[1]; } else { root->key = parent->key; root->data = parent->data; @@ -90,18 +90,18 @@ vieter_tree_node *vieter_tree_node_balance(vieter_tree_node *node) { left = parent; right = node; - children[0] = grand_parent->left; - children[1] = parent->left; - children[2] = node->left; - children[3] = node->right; + children[0] = grand_parent->children[0]; + children[1] = parent->children[0]; + children[2] = node->children[0]; + children[3] = node->children[1]; } vieter_tree_node_set(left, vieter_tree_node_black); vieter_tree_node_set(right, vieter_tree_node_black); vieter_tree_node_unset(root, vieter_tree_node_black); - left->left = children[0]; - left->right = children[1]; + left->children[0] = children[0]; + left->children[1] = children[1]; if (children[0] != NULL) children[0]->parent = left; @@ -109,8 +109,8 @@ vieter_tree_node *vieter_tree_node_balance(vieter_tree_node *node) { if (children[1] != NULL) children[1]->parent = left; - right->left = children[2]; - right->right = children[3]; + right->children[0] = children[2]; + right->children[1] = children[3]; if (children[2] != NULL) children[2]->parent = right; @@ -118,8 +118,8 @@ vieter_tree_node *vieter_tree_node_balance(vieter_tree_node *node) { if (children[3] != NULL) children[3]->parent = right; - root->left = left; - root->right = right; + root->children[0] = left; + root->children[1] = right; left->parent = root; right->parent = root; diff --git a/src/tree/vieter_tree_node.c b/src/tree/vieter_tree_node.c index b7e82a8..ca506b9 100644 --- a/src/tree/vieter_tree_node.c +++ b/src/tree/vieter_tree_node.c @@ -13,11 +13,7 @@ void vieter_tree_node_add_child(vieter_tree_node *parent, uint64_t key, return; } - if (key < parent->key) { - parent->left = child; - } else { - parent->right = child; - } + parent->children[key > parent->key] = child; if (child != NULL) { child->parent = parent; @@ -28,14 +24,14 @@ void vieter_tree_node_replace_with_child(vieter_tree_node *to_replace, vieter_tree_node *replacement) { to_replace->key = replacement->key; to_replace->data = replacement->data; - to_replace->left = replacement->left; - to_replace->right = replacement->right; + to_replace->children[0] = replacement->children[0]; + to_replace->children[1] = replacement->children[1]; - if (to_replace->left != NULL) - to_replace->left->parent = to_replace; + if (to_replace->children[0] != NULL) + to_replace->children[0]->parent = to_replace; - if (to_replace->right != NULL) - to_replace->right->parent = to_replace; + if (to_replace->children[1] != NULL) + to_replace->children[1]->parent = to_replace; } vieter_tree_error vieter_tree_node_insert(vieter_tree_node *root, uint64_t key, @@ -49,12 +45,7 @@ vieter_tree_error vieter_tree_node_insert(vieter_tree_node *root, uint64_t key, } parent = node; - - if (key < parent->key) { - node = parent->left; - } else { - node = parent->right; - } + node = node->children[key > parent->key]; } vieter_tree_node *new_node = vieter_tree_node_init(); @@ -79,11 +70,7 @@ vieter_tree_error vieter_tree_node_search_node(vieter_tree_node **out, return vieter_tree_ok; } - if (key < node->key) { - node = node->left; - } else { - node = node->right; - } + node = node->children[key > node->key]; } return vieter_tree_not_present; @@ -114,13 +101,13 @@ vieter_tree_error vieter_tree_node_remove(void **out, vieter_tree_node *root, *out = target->data; - if (target->left == NULL && target->right == NULL) { + if (target->children[0] == NULL && target->children[1] == NULL) { vieter_tree_node_add_child(target->parent, target->key, NULL); vieter_tree_node_free(target); - } else if ((target->left == NULL) ^ (target->right == NULL)) { + } else if ((target->children[0] == NULL) ^ (target->children[1] == NULL)) { vieter_tree_node *child = - target->left != NULL ? target->left : target->right; + target->children[0] != NULL ? target->children[0] : target->children[1]; if (target->parent != NULL) { vieter_tree_node_add_child(target->parent, child->key, child); @@ -131,10 +118,10 @@ vieter_tree_error vieter_tree_node_remove(void **out, vieter_tree_node *root, } } else { - vieter_tree_node *replacement = target->right; + vieter_tree_node *replacement = target->children[1]; - while (replacement->left != NULL) { - replacement = replacement->left; + while (replacement->children[0] != NULL) { + replacement = replacement->children[0]; } // We use replacement->key here because the right child can be NULL, so @@ -142,7 +129,7 @@ vieter_tree_error vieter_tree_node_remove(void **out, vieter_tree_node *root, // will still get placed into the right location because of how binary // trees work. vieter_tree_node_add_child(replacement->parent, replacement->key, - replacement->right); + replacement->children[1]); target->key = replacement->key; target->data = replacement->data; diff --git a/src/tree/vieter_tree_node.h b/src/tree/vieter_tree_node.h index 5e74280..21bbb81 100644 --- a/src/tree/vieter_tree_node.h +++ b/src/tree/vieter_tree_node.h @@ -6,15 +6,17 @@ #include typedef enum vieter_tree_node_flag { - vieter_tree_node_black = ((uint8_t)1) << 0 + vieter_tree_node_black = ((uint8_t)1) << 0, + // This flag is used to index the children array. If this flag isn't set, + // it'll evaluate to false, or index 0 in the children array. + vieter_tree_node_right = ((uint8_t)1) << 1 } vieter_tree_node_flag; typedef struct vieter_tree_node { uint64_t key; void *data; struct vieter_tree_node *parent; - struct vieter_tree_node *left; - struct vieter_tree_node *right; + struct vieter_tree_node *children[2]; uint8_t flags; } vieter_tree_node;