private int _query(SegmentTreeNode node, int start, int end)
{
if (start <= node.Start && node.End <= end)
{
return(node.Value);
}
int retValue = 0;
if (SegmentTreeType == SegmentTreeType.Max)
{
retValue = int.MinValue;
}
else if (SegmentTreeType == SegmentTreeType.Min)
{
retValue = int.MaxValue;
}
if (start <= (node.Start + node.End) / 2)
{
retValue = getValueByType(retValue, _query(node.LeftChild, start, end));
}
if ((node.Start + node.End) / 2 + 1 <= end)
{
retValue = getValueByType(retValue, _query(node.RightChild, start, end));
}
return(retValue);
}
public SegmentTreeNode BuildTree(int[] inputArray)
{
if (inputArray == null || inputArray.Length == 0)
{
return(null);
}
Root = _build(0, inputArray.Length - 1, inputArray);
return(Root);
}
private SegmentTreeNode _build(int start, int end, int[] array)
{
SegmentTreeNode node = new SegmentTreeNode(start, end, array[start]);
if (start == end)
{
return(node);
}
node.LeftChild = _build(start, (start + end) / 2, array);
node.RightChild = _build((start + end) / 2 + 1, end, array);
node.Value = getValueByType(node.LeftChild.Value, node.RightChild.Value);
return(node);
}
private void _update(SegmentTreeNode node, int index, int value)
{
if (node.Start == node.End && node.Start == index)
{
node.Value = value;
return;
}
if (index <= (node.Start + node.End) / 2)
{
_update(node.LeftChild, index, value);
}
else
{
_update(node.RightChild, index, value);
}
node.Value = getValueByType(node.LeftChild.Value, node.RightChild.Value);
}