FenwickTree structure for c++

FenwickTree.cpp

struct FenvickTree {
	struct Node {
		int Value;
		int Sum;
		int Parent;
		int Next;
	};

	vector<Node> Tree;

	int Sum(int index) {
		if (index < 0) return 0;
		int sum = 0;
		do {
			sum += Tree[index].Sum;
			index = Tree[index].Parent;
		} while (index != -1);
		return sum;
	}

	int Sum(int left, int right) {
		return Sum(right) - Sum(left - 1);
	}

	int Calc(int left, int right) {
		int sum = 0;
		for (int i = left; i < right; ++i) {
			sum += Tree[i].Value;
		}
		return sum;
	}

	void Initialize(vector<int> * values) {
		int size = (*values).size();
		Node zero;
		zero.Next = -1;
		zero.Parent = -1;
		zero.Sum = 0;
		zero.Value = 0;
		Tree.resize(size, zero);
		
		for (int i = 0; i < size; ++i) {
			Tree[i].Value = (*values)[i];
			int p = (i & (i + 1)) - 1;
			if (p < 0) Tree[i].Parent = -1;
			else Tree[i].Parent = p;
			int n = i + 1;
			n += (n & (-n)) - 1;
			Tree[i].Next = n;
		}

		for (int i = 0; i < size; ++i) {
			int value = Tree[i].Value;
			int j = i;
			do {
				Tree[j].Sum += value;
				j = Tree[j].Next;
			} while (j < size);
		}
	}

	void Push(int value) {
		Node node;
		node.Value = value;
		node.Sum = value;
		node.Next = -1;
		int p = (Tree.size() & (Tree.size() + 1)) - 1;
		if (p < 0) node.Parent = -1;
		else node.Parent = p;
		int s = Tree.size() + 1;
		int n = s + (s & (-s)) - 1;
		node.Next = n;
		node.Sum += Calc(s - (s & (-s)), s - 1);
		Tree.push_back(node);
	}

	void Update(int index, int value) {
		int dif = value - Tree[index].Value;
		Tree[index].Value = value;
		do {
			Tree[index].Sum += dif;
			index = Tree[index].Next;
		} while (index < Tree.size());
	}
};