saidx_t range_max(const saidx_t *segment_tree,
                  size_t inner_node_count,
                  size_t first, size_t last)
{
	saidx_t value = -1;
	size_t left = first + inner_node_count;
	size_t right = last + inner_node_count - 1;
	while (left <= right)
	{
		if (left % 2 && value < segment_tree[left])
			value = segment_tree[left];
		if (!(right % 2) && value < segment_tree[right])
			value = segment_tree[right];
		left = (left + 1) / 2;
		right = (right - 1) / 2;
	}
	return value;
}

void increase(saidx_t *segment_tree, size_t inner_node_count,
              size_t i, saidx_t value)
{
	for (i += inner_node_count; i; i /= 2)
		if (segment_tree[i] < value)
			segment_tree[i] = value;
}

void set(saidx_t *segment_tree, size_t inner_node_count,
         size_t i, saidx_t value)
{
	segment_tree[i += inner_node_count] = value;
	while (i /= 2)
		segment_tree[i] =
			max(segment_tree[i * 2], segment_tree[i * 2 + 1]);
}