HORRIBLE SegmentTreeNode

HORRIBLE SegmentTreeNode.cpp

struct SegmentTreeNode {
  int start, end; // this node is responsible for the segment [start...end]
  ll total, pendingUpdate;
  
  SegmentTreeNode() : total(0), pendingUpdate(0) {}
  
  void assignLeaf(ll value) {
    total = value;
  }
  
  void merge(SegmentTreeNode& left, SegmentTreeNode& right) {
    total = left.total + right.total;
    if (left.pendingUpdate > 0)
      total += left.pendingUpdate * (left.end - left.start + 1);
    if (right.pendingUpdate > 0)
      total += right.pendingUpdate * (right.end - right.start + 1);
  }
  
  ll query() {
    return total;
  }
  
  bool hasPendingUpdate() {
    return pendingUpdate != 0;
  }
  
  void applyPendingUpdate() {
    total += (end - start + 1) * pendingUpdate;
    pendingUpdate = 0;
  }
  
  void addUpdate(ll value) {
    pendingUpdate += value;
  }
  
  ll getPendingUpdate() {
    return pendingUpdate;
  }
};