Deletion algorithm fix

wolkykim · Jul 22, 2023 · 383f2ff · 383f2ff
1 parent c9d2863
commit 383f2ff
Showing 1 changed file with 14 additions and 11 deletions.
diff --git a/src/containers/qtreetbl.c b/src/containers/qtreetbl.c
@@ -1062,17 +1062,20 @@ static qtreetbl_obj_t *rotate_right(qtreetbl_obj_t *obj) {
 
 static qtreetbl_obj_t *move_red_left(qtreetbl_obj_t *obj) {
     flip_color(obj);
-    if (obj->right && is_red(obj->right->left)) {
+    if (is_red(obj->right->left)) {
         obj->right = rotate_right(obj->right);
         obj = rotate_left(obj);
         flip_color(obj);
+        if (is_red(obj->right->right)) {
+            obj->right = rotate_left(obj->right);
+        }
     }
     return obj;
 }
 
 static qtreetbl_obj_t *move_red_right(qtreetbl_obj_t *obj) {
     flip_color(obj);
-    if (obj->left && is_red(obj->left->left)) {
+    if (is_red(obj->left->left)) {
         obj = rotate_right(obj);
         flip_color(obj);
     }
@@ -1082,16 +1085,15 @@ static qtreetbl_obj_t *move_red_right(qtreetbl_obj_t *obj) {
 static qtreetbl_obj_t *fix(qtreetbl_obj_t *obj) {
     // rotate right red to left
     if (is_red(obj->right)) {
+        if (is_red(obj->right->left)) {
+            obj->right = rotate_right(obj->right);
+        }
         obj = rotate_left(obj);
     }
     // rotate left red-red to right
-    if (obj->left && is_red(obj->left) && is_red(obj->left->left)) {
+    if (is_red(obj->left) && is_red(obj->left->left)) {
         obj = rotate_right(obj);
     }
-    // split 4-nodes
-    if (is_red(obj->left) && is_red(obj->right)) {
-        flip_color(obj);
-    }
     return obj;
 }
 
@@ -1226,18 +1228,19 @@ static qtreetbl_obj_t *remove_obj(qtreetbl_t *tbl, qtreetbl_obj_t *obj,
 
     if (tbl->compare(name, namesize, obj->name, obj->namesize) < 0) {  // left
         // move red left
-        if (obj->left && (!is_red(obj->left) && !is_red(obj->left->left))) {
+        if (obj->left != NULL
+                && (!is_red(obj->left) && !is_red(obj->left->left))) {
             obj = move_red_left(obj);
         }
         // keep going down to the left
         obj->left = remove_obj(tbl, obj->left, name, namesize);
     } else {  // right or equal
-        if (is_red(obj->left) && !is_red(obj->right)) {
+        if (is_red(obj->left)) {
             obj = rotate_right(obj);
         }
         // remove if equal at the bottom
-        if (tbl->compare(name, namesize, obj->name, obj->namesize)
-                == 0&& obj->right == NULL) {
+        if (tbl->compare(name, namesize, obj->name, obj->namesize) == 0
+                && obj->right == NULL) {
             free(obj->name);
             free(obj->data);
             free(obj);