树剖求吊
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  • 发布时间2023/5/27 20:56
  • 上次更新2023/10/23 14:33:09
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树剖求吊
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f_hxr_楼主2023/5/27 20:56

rt,上次发了一个逆天标题效果甚微。改来改去始终只对了最后一个#11.

#include<bits/stdc++.h>
using namespace std;
const int maxn=5e5+7;
int N,M,R,P,w[maxn],dep[maxn];
int head[maxn],nxt[maxn],to[maxn],cnt;//邻接表全家桶 
int Fa[maxn],Hd[maxn],Hson[maxn],SZ[maxn],id[maxn];
//树剖全家桶(爹,i的重链头,重儿子,子树大小,在线段树的位置 )
struct node{int l,r,dat,add;}tree[maxn];
void edge(int U,int V){
	nxt[++cnt]=head[U];to[cnt]=V;head[U]=cnt;
	nxt[++cnt]=head[V];to[cnt]=U;head[V]=cnt;
	return;
}
//以下为线段树 
int ls(int p){return p<<1;}
int rs(int p){return p<<1|1;}
int Mid(int l,int r){return (l+r)>>1;}
void build(int l,int r,int p){//建树 
	tree[p].l=l;tree[p].r=r;
	if(l==r){tree[p].dat=w[l]%P;return;}
	int mid=Mid(l,r);
	build(l,mid,ls(p));build(mid+1,r,rs(p));
	tree[p].dat=(tree[ls(p)].dat+tree[rs(p)].dat)%P;
	return;
}
void lazy(int p){//懒标记
	if(tree[p].add){
		tree[ls(p)].dat+=tree[p].add*(tree[ls(p)].r-tree[ls(p)].l+1);
		tree[rs(p)].dat+=tree[p].add*(tree[rs(p)].r-tree[rs(p)].l+1);
		tree[ls(p)].add+=tree[p].add;tree[rs(p)].add+=tree[p].add;
		tree[ls(p)].dat%=P;tree[rs(p)].dat%=P; 
		tree[p].add=0;
	}
	return; 
}
void change(int p,int l,int r,int k){
	//cout<<"changeing L:"<<l<<" R: "<<r<<endl; 
	//cout<<"现在事节点 "<<p<<"从 "<<tree[p].l<<" 到 "<<tree[p].r<<endl;
	if(l<=tree[p].l&&r>=tree[p].r){
		tree[p].dat+=1LL*k*(tree[p].r-tree[p].l+1);
		tree[p].dat%P;
		tree[p].add+=k;
		return;
	}
	int mid=Mid(tree[p].l,tree[p].r);
	if(l<=mid)change(ls(p),l,r,k);
	if(r>mid)change(rs(p),l,r,k);
	tree[p].dat=(tree[ls(p)].dat+tree[rs(p)].dat)%P;
	return;
}
long long ask(int p,int l,int r){
	if(l<=tree[p].l&&r>=tree[p].r)return tree[p].dat%P;
	lazy(p);
	int mid=Mid(tree[p].l,tree[p].r);
	long long ret=0;
	if(l<=mid)ret+=ask(ls(p),l,r);
	if(r>mid)ret+=ask(rs(p),l,r);
	return ret%P;
}
//线段树部分结束 
//它 来 了
int dfs1(int u,int fa){
	SZ[u]=1;Fa[u]=fa;dep[u]=dep[fa]+1;
	for(int i=head[u];i;i=nxt[i]){
		int v=to[i];
		if(v!=fa){
			SZ[u]+=dfs1(v,u);
			if(SZ[v]>SZ[Hson[u]])Hson[u]=v;
		}
	}
	return SZ[u]; 
}
void dfs2(int u,int fa,int _H){//当前节点,爹,重链头 
	id[u]=++cnt;Hd[u]=_H;
	if(Hson[u])dfs2(Hson[u],u,_H);
	for(int i=head[u];i;i=nxt[i])
		if(to[i]!=fa&&to[i]!=Hson[u])dfs2(to[i],u,to[i]);
	return;
}
void add(int u,int v,int w){
	w%=P;
	while(Hd[u]!=Hd[v]){
		int hu=Hd[u],hv=Hd[v];
		if(dep[hu]<dep[hv])swap(u,v),swap(hu,hv);
		change(1,id[hu],id[u],w);
		u=Fa[hu];
	}
	if(dep[u]>dep[v])swap(u,v);
	change(1,id[u],id[v],w);
	return;
}
int addPage(int u,int v){
	int ret=0;
	while(Hd[u]!=Hd[v]){
		int hu=Hd[u],hv=Hd[v];
		if(dep[hu]<dep[hv])swap(u,v),swap(hu,hv);
		ret+=ask(1,id[hu],id[u]);
		ret%=P;
		u=Fa[hu];
	}
	if(dep[u]>dep[v])swap(u,v);
	return(ret+ask(1,id[u],id[v]))%P;
}
//E · N · D 
int main(){
	scanf("%d%d%d%d",&N,&M,&R,&P);
	for(int i=1;i<=N;i++)scanf("%d",&w[i]);
	for(int i=1;i<N;i++){int a,b;scanf("%d%d",&a,&b);edge(a,b);}
	cnt=0;//!!!!!!!
	dfs1(R,0);
	dfs2(R,0,R); 
	build(1,N,1);
	while(M--){
		//cout<<"Case "<<M+1<<endl;
		int op,x,y,z;
		scanf("%d",&op);
		if(op==1){
			//cout<<"修改\n";
			scanf("%d%d%d",&x,&y,&z);
			add(x,y,z);
		}else if(op==2){
			//cout<<"查询\n";
			scanf("%d%d",&x,&y);
			printf("%d\n",addPage(x,y)%P);
		}else if(op==3){
			//cout<<"修改\n";
			scanf("%d%d",&x,&y);
			change(1,id[x],id[x]+SZ[x]-1,y);
		}else{
			//cout<<"查询\n";
			scanf("%d",&x);
			printf("%d\n",ask(1,id[x],id[x]+SZ[x]-1)%P);
		}
	}
	return 0;
}
2023/5/27 20:56
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