GSS1 segment tree node

GSS1 segment tree node.cpp

struct SegmentTreeNode {
  int prefixMaxSum, suffixMaxSum, maxSum, sum;
  
  void assignLeaf(int value) {
    prefixMaxSum = suffixMaxSum = maxSum = sum = value;
  }
  
  void merge(SegmentTreeNode& left, SegmentTreeNode& right) {
    sum = left.sum + right.sum;
    prefixMaxSum = max(left.prefixMaxSum, left.sum + right.prefixMaxSum);
    suffixMaxSum = max(right.suffixMaxSum, right.sum + left.suffixMaxSum);
    maxSum = max(prefixMaxSum, max(suffixMaxSum, max(left.maxSum, max(right.maxSum, left.suffixMaxSum + right.prefixMaxSum))));
  }
  
  int getValue() {
    return maxSum;
  }
};