线段树c++实现

//线段树
struct Node
{
	int l, r, sum;
	int pre;//标记
	Node():l(0),r(0),sum(0),pre(0){}
};
int creat_tree(vector&v, int i, int j,vector&Tree,int x)//创建一个线段树，下标从0开始
{
	Tree[x].l = i; Tree[x].r = j;
	if (i == j)//左右端点相等即叶子节点
	{
		Tree[x].sum = v[i];
		return Tree[x].sum;
	}
	int mid = i + j >> 1;//中点
	int left = creat_tree(v, i, mid, Tree, 2 * x + 1);
	int right = creat_tree(v, mid + 1, j, Tree, 2 * x + 2);
	Tree[x].sum = left+right;
	return Tree[x].sum;
}
void alter_pre(vector&Tree, int x)
{
	int a = 2 * x + 1, b = 2 * x + 2;
	if (Tree[a].l != 0)
	{
		Tree[a].sum += (Tree[a].r - Tree[a].l + 1)*Tree[x].pre;
		Tree[a].pre += Tree[x].pre;
	}
	if (Tree[b].l != 0)
	{
		Tree[b].sum += (Tree[b].r - Tree[b].l + 1)*Tree[x].pre;
		Tree[b].pre += Tree[x].pre;
	}
	Tree[x].pre = 0;
}
int find_tree(vector&Tree, int x, int i,int j)//区间查询
{
	if (Tree[x].l > j || Tree[x].r < i)return 0;//如果不包含区间
	if (Tree[x].l >= i&&Tree[x].r <= j)return Tree[x].sum;//区间被包含
	 //区间没有被全部包含
	if (Tree[x].pre != 0)//检测标记
	{
		alter_pre(Tree, x);
	}
	int left = find_tree(Tree, 2 * x + 1, i, j);
	int right = find_tree(Tree, 2 * x + 2, i, j);
	return left + right;
}
void alter_tree(vectorTree, int x, int i, int j, int m)//区间修改
{
	if (Tree[x].l > j || Tree[x].r < i)return ;
	if (Tree[x].l >= i&&Tree[x].r <= j)//区间完全包含
	{
		int count = (Tree[x].r - Tree[x].l + 1)*m;//增加为节点个数*修改值
		Tree[x].sum += count;//加上修改值
		Tree[x].pre += m;//设置标记
		int n = x;
		while (n != 0)//向上修改
		{
			n = (n - 1) >> 1;
			Tree[x].sum += count;
		}
		return;
	}
	//如果没有全包含
	if (Tree[x].pre != 0)//修改标记
	{
		alter_pre(Tree, x);
	}
	alter_tree(Tree, 2 * x + 1, i, j, m);//左子树
	alter_tree(Tree, 2 * x + 2, i, j, m);//右子树
}

原理：

和堆排序一样数组中实现二叉树搜索树，区间增加，区间查询，延迟传递