Fix: heap sift-down to the right happened even when it shouldn't have
parent
0b88775b0c
commit
a22d229c01
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@ -3,14 +3,14 @@ class SearchHeap<K, T> {
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final K Function(T) getKey;
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final int Function(T) getPriority;
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List<(T, K, int)> _items;
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Map<K, int> _positionByKey;
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Map<K, int> _indexByKey;
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SearchHeap({
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required this.getKey,
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required this.getPriority,
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}):
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_items = [],
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_positionByKey = {};
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_indexByKey = {};
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factory SearchHeap.fromItems(
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List<T> items,
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@ -43,11 +43,11 @@ class SearchHeap<K, T> {
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_items.add(heapItem);
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while (i > 0 && _items[(i-1) >> 1].$3 > thisKey) {
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_items[i] = _items[(i-1) >> 1];
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_positionByKey[_items[i].$2] = i;
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_indexByKey[_items[i].$2] = i;
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i = (i-1) >> 1;
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}
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_items[i] = heapItem;
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_positionByKey[heapItem.$2] = i;
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_indexByKey[heapItem.$2] = i;
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}
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T removeFirst() {
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@ -55,7 +55,7 @@ class SearchHeap<K, T> {
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throw StateError("No element");
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}
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final T firstItem = _items[0].$1;
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_positionByKey.remove(_items[0].$2);
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_indexByKey.remove(_items[0].$2);
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if (_items.length < 2) {
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_items.length--;
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return firstItem;
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@ -71,34 +71,34 @@ class SearchHeap<K, T> {
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if (leftIndex < _items.length && itemToMove.$3 > _items[leftIndex].$3) {
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if (rightIndex < _items.length && _items[leftIndex].$3 > _items[rightIndex].$3) {
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_items[i] = _items[rightIndex];
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_positionByKey[_items[i].$2] = i;
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_indexByKey[_items[i].$2] = i;
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i = rightIndex;
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} else {
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_items[i] = _items[leftIndex];
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_positionByKey[_items[i].$2] = i;
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_indexByKey[_items[i].$2] = i;
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i = leftIndex;
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}
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} else if (rightIndex < _items.length && _items[leftIndex].$3 > _items[rightIndex].$3) {
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} else if (rightIndex < _items.length && itemToMove.$3 > _items[rightIndex].$3) {
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_items[i] = _items[rightIndex];
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_positionByKey[_items[i].$2] = i;
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_indexByKey[_items[i].$2] = i;
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i = rightIndex;
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} else {
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stop = true;
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}
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}
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_items[i] = itemToMove;
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_positionByKey[itemToMove.$2] = i;
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_indexByKey[itemToMove.$2] = i;
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return firstItem;
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}
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void updateElement(K key) {
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int i = _positionByKey[key]!;
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int i = _indexByKey[key]!;
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final (T, K, int) item = (_items[i].$1, _items[i].$2, getPriority(_items[i].$1));
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bool dontBubbleDown = false;
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while (i > 0 && _items[(i-1) >> 1].$3 > item.$3) {
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dontBubbleDown = true;
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_items[i] = _items[(i-1) >> 1];
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_positionByKey[_items[i].$2] = i;
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_indexByKey[_items[i].$2] = i;
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i = (i-1) >> 1;
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}
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int leftIndex, rightIndex;
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@ -108,28 +108,47 @@ class SearchHeap<K, T> {
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if (leftIndex < _items.length && item.$3 > _items[leftIndex].$3) {
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if (rightIndex < _items.length && _items[leftIndex].$3 > _items[rightIndex].$3) {
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_items[i] = _items[rightIndex];
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_positionByKey[_items[i].$2] = i;
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_indexByKey[_items[i].$2] = i;
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i = rightIndex;
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} else {
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_items[i] = _items[leftIndex];
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_positionByKey[_items[i].$2] = i;
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_indexByKey[_items[i].$2] = i;
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i = leftIndex;
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}
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} else if (rightIndex < _items.length && _items[leftIndex].$3 > _items[rightIndex].$3) {
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} else if (rightIndex < _items.length && item.$3 > _items[rightIndex].$3) {
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_items[i] = _items[rightIndex];
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_positionByKey[_items[i].$2] = i;
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_indexByKey[_items[i].$2] = i;
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i = rightIndex;
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} else {
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dontBubbleDown = true;
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}
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}
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_items[i] = item;
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_positionByKey[item.$2] = i;
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_indexByKey[item.$2] = i;
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}
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@override
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String toString() => _items.map(((T, K, int) item) => item.$1).toString();
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List<T> get debugItems => _items.map(((T, K, int) item) => item.$1).toList();
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Map<K, int> get debugPositionByKey => _indexByKey;
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bool get debugHeapValidity {
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for (int i = 1; i < _items.length; i++) {
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if (_items[i].$3 < _items[(i-1) >> 1].$3) {
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return false;
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}
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}
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return true;
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}
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bool get debugDictionaryValidity {
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for (final MapEntry<K, int>(key: K key, value: int index) in _indexByKey.entries) {
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if (_items[index].$2 != key) {
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return false;
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}
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}
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return true;
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}
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}
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