P5055 【模板】可持久化文艺平衡树

链接

luogu

思路

可持久化fhq-treap套一套就行了，pushdown和split都要可持久化，但merge不用可持久。以前以为很难一直没看，就是个板子。

错误

t[++num].sum=x;t[num].val=x;
t[++num].sum=t[num].val=x;

这两句话居然不一样。
我靠我靠我靠，调试了一下午。

代码

#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int _=2e5+7;
ll read() {ll x=0,f=1;char s=getchar();for(;s>'9'||s<'0';s=getchar()) if(s=='-') f=-1;for(;s>='0'&&s<='9';s=getchar()) x=x*10+s-'0';return x*f;
}
namespace fhq_treap {#define ls t[u].ch[0]#define rs t[u].ch[1]int num;struct node {int ch[2],siz,pri,lazy;ll val,sum;}t[_*80];int make_node(ll x) {t[++num].sum=x;t[num].val=x;t[num].pri=rand(),t[num].siz=1;return num;}void pushup(int u) {t[u].siz=t[ls].siz+t[rs].siz+1;t[u].sum=t[ls].sum+t[rs].sum+t[u].val;}int copy_node(int u) {t[++num]=t[u];return num;}void pushdown(int u) {if(t[u].lazy) {if(ls) ls=copy_node(ls);if(rs) rs=copy_node(rs);if(ls) t[ls].lazy^=1;if(rs) t[rs].lazy^=1;swap(ls,rs);t[u].lazy^=1;}}int merge(int x,int y) {if(!x||!y) return x+y;pushdown(x),pushdown(y);if(t[x].pri<t[y].pri) {t[x].ch[1]=merge(t[x].ch[1],y);pushup(x);return x;} else {t[y].ch[0]=merge(x,t[y].ch[0]);pushup(y);return y;}   }void split(int u,int k,int &x,int &y) {if(!u) x=y=0;else {pushdown(u);u=copy_node(u);if(t[ls].siz+1<=k)x=u,split(rs,k-t[ls].siz-1,t[x].ch[1],y);elsey=u,split(ls,k,x,t[y].ch[0]);pushup(u);}}
}
using namespace fhq_treap;
int rt[_];
int main() {srand(19260817); int T=read();ll lastans=0;for(int i=1;i<=T;++i) {int super_cool=read(),opt=read(),x,y,z;if(opt==1) {ll p=read()^lastans,v=read()^lastans;split(rt[super_cool],p,x,y);rt[i]=merge(merge(x,make_node(v)),y);} else if(opt==2) {ll p=read()^lastans;split(rt[super_cool],p,x,z);split(x,p-1,x,y);rt[i]=merge(x,z);} else if(opt==3) {ll l=read()^lastans,r=read()^lastans;split(rt[super_cool],r,x,z);split(x,l-1,x,y);t[y].lazy^=1;rt[i]=merge(merge(x,y),z);} else {ll l=read()^lastans,r=read()^lastans;split(rt[super_cool],r,x,z);split(x,l-1,x,y);printf("%lld\n",lastans=t[y].sum);rt[i]=merge(merge(x,y),z);}}return 0;
}