HORRIBLE query() and update()

HORRIBLE query() and update().cpp

SegmentTreeNode query(int stIndex, int start, int end) {
  if (nodes[stIndex].start == start && nodes[stIndex].end == end) {
    SegmentTreeNode result = nodes[stIndex];
    if (result.hasPendingUpdate())
      result.applyPendingUpdate();
    return result;
  }
  
  int mid = (nodes[stIndex].start + nodes[stIndex].end) >> 1,
      leftChildIndex = stIndex << 1,
      rightChildIndex = leftChildIndex + 1;			
  SegmentTreeNode result;
  
  if (start > mid)
    result = query(rightChildIndex, start, end);
  else if (end <= mid)
    result = query(leftChildIndex, start, end);
  else {
    SegmentTreeNode leftResult = query(leftChildIndex, start, mid),
                    rightResult = query(rightChildIndex, mid+1, end);
    result.start = leftResult.start;
    result.end = rightResult.end;
    result.merge(leftResult, rightResult);
  }
  
  if (nodes[stIndex].hasPendingUpdate()) {
    result.addUpdate(nodes[stIndex].getPendingUpdate());
    result.applyPendingUpdate();
  }		
  return result;
}

void update(int stIndex, int start, int end, UpdateType value) {
  if (nodes[stIndex].start == start && nodes[stIndex].end == end) {
    nodes[stIndex].addUpdate(value);
    return;
  }
  
  int mid = (nodes[stIndex].start + nodes[stIndex].end) >> 1,
    leftChildIndex = stIndex << 1,
    rightChildIndex = leftChildIndex + 1;
  	
  if (start > mid)
    update(rightChildIndex, start, end, value);
  else if (end <= mid)
    update(leftChildIndex, start, end, value);
  else {
    update(leftChildIndex, start, mid, value);
    update(rightChildIndex, mid+1, end, value);
  }
  nodes[stIndex].merge(nodes[leftChildIndex], nodes[rightChildIndex]);
}