private void Build(int treeArrayIndex, int segmentStartIndex, int segmentEndIndex)
{
if (segmentStartIndex == segmentEndIndex)
{
_treeArray[treeArrayIndex] = new SumQueryObject(segmentStartIndex, 0);
return;
}
int leftChildTreeArrayIndex = 2 * treeArrayIndex + 1;
int rightChildTreeArrayIndex = leftChildTreeArrayIndex + 1;
int leftChildSegmentEndIndex = (segmentStartIndex + segmentEndIndex) / 2;
Build(leftChildTreeArrayIndex, segmentStartIndex, leftChildSegmentEndIndex);
Build(rightChildTreeArrayIndex, leftChildSegmentEndIndex + 1, segmentEndIndex);
_treeArray[treeArrayIndex] = _treeArray[leftChildTreeArrayIndex].Combine(_treeArray[rightChildTreeArrayIndex]);
}
public void Update(SumQueryObject updatedLeftChild, SumQueryObject updatedRightChild) => SumWithoutRangeAddition = updatedLeftChild.Sum + updatedRightChild.Sum;
public SumQueryObject Combine(SumQueryObject rightAdjacentObject)
=> new SumQueryObject(
segmentStartIndex: SegmentStartIndex,
segmentEndIndex: rightAdjacentObject.SegmentEndIndex,
sumWithoutRangeAddition: Sum + rightAdjacentObject.Sum);
