FLIPCOIN SegmentTreeNode

FLIPCOIN SegmentTreeNode.cpp

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