【splay】poj3468

存个splay的板子，建树的姿势非常巧妙

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cmath>
#include<cstring>
#include<algorithm>
#define lc(x) tree[x].c[0]
#define rc(x) tree[x].c[1]
#define sum(x) tree[x].sum
#define num(x) tree[x].num
#define biao(x) tree[x].biao
#define fa(x) tree[x].fa
#define da(x) tree[x].da
using namespace std;
struct rec
{
	int c[2],fa;
	long long sum,num,biao,da;
}tree[600010];
int Q,n,root,a[200100];
void updata(long long x)
{
	if (lc(x)!=0)
	{
		biao(lc(x))+=biao(x);
		da(lc(x))+=biao(x);
		sum(lc(x))+=biao(x)*num(lc(x));
	}
	if (rc(x)!=0)
	{
		biao(rc(x))+=biao(x);
		da(rc(x))+=biao(x);
		sum(rc(x))+=biao(x)*num(rc(x));
	}
	biao(x)=0;
}
void rot(long long x,long long w)
{
	int q=fa(x);
	int p=fa(fa(x));
	updata(q);
	updata(x);
	if (p!=0) 
	{
		if (lc(p)==q) lc(p)=x;
		else rc(p)=x;
	}
	fa(x)=p;
	if (tree[x].c[w]!=0) {tree[q].c[w^1]=tree[x].c[w];fa(tree[x].c[w])=q;}
	else {tree[q].c[w^1]=0;}
	tree[x].c[w]=q;fa(q)=x;
	sum(q)=sum(lc(q))+sum(rc(q))+da(q);
	num(q)=num(lc(q))+num(rc(q))+1;
	sum(x)=sum(lc(x))+sum(rc(x))+da(x);
	num(x)=num(lc(x))+num(rc(x))+1;
}//旋转细节要注意
void splay(long long x,long long w)
{
	while (fa(x)!=w)
	{
		if (lc(fa(x))==x) rot(x,1);
		else rot(x,0);
	}
	updata(x);
}
int maketree(int l,int r,int w)
{
	if (r<l) return 0;
	int now=(l+r)>>1;
	tree[now].c[0]=maketree(l,now-1,now);
	tree[now].c[1]=maketree(now+1,r,now);
	tree[now].fa=w;
	tree[now].da=a[now-1];
	tree[now].num=num(lc(now))+num(rc(now))+1;
	tree[now].sum=sum(lc(now))+sum(rc(now))+da(now);
	return now;
}//巧妙的递归建树
void input()
{
	scanf("%d%d",&n,&Q);
	for (int i=1;i<=n;i++)
		scanf("%d",&a[i]);
}
void work()
{
	char ch;
	int l,r,k;
	for (int i=1;i<=Q;i++)
	{
		scanf(" %c",&ch);
		if (ch=='C')
		{
			scanf("%d%d%d",&l,&r,&k);
			splay(l,0);
			splay(r+2,l);
			biao(lc(r+2))+=k;
			sum(lc(r+2))+=(num(lc(r+2))*k);
			da(lc(r+2))+=k;
			continue;
		}
		if (ch=='Q')
		{
			scanf("%d%d",&l,&r);
			splay(l,0);
			splay(r+2,l);
			printf("%lld\n",sum(lc(r+2)));
		}
	}
}
int main()
{
	//freopen("test.in","r",stdin);
	input();
	maketree(1,n+2,0);
	work();
	return 0;
}