为啥会T啊,30pts求调壶关
查看原帖
为啥会T啊,30pts求调壶关
684285
Makerlike楼主2024/8/6 19:07
#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
#define int long long
template<typename T>
inline void read(T &x) {x=0;char ch=getchar();int f=1;while(!isdigit(ch)){if(ch=='-')f*=-1;ch=getchar();}while(isdigit(ch)){x=x*10+ch-48;ch=getchar();}x*=f;}
template<typename T, typename... Args>
inline void read(T &first, Args& ... args) {read(first);read(args...);}
template<typename T>
inline void write(T arg) {T x=arg;if(x<0) {putchar('-');x=-x;}if(x>9) {write(x/10);}putchar(x%10+'0');}
template<typename T, typename ... Ts>
inline void write(T arg, Ts ... args) {write(arg);if(sizeof...(args)!=0) {putchar(' ');write(args ...);}}
const int N=4e5+10;
const int INF=0x3f3f3f3f3f3f3f3f;
int n,m,a[N];
struct Edge{
	int v,nxt;
}e[N];
int hd[N],tt;
void init(){
	memset(hd,-1,sizeof(hd));
}
void add(int x,int y){
	e[++tt].v=y;
	e[tt].nxt=hd[x];
	hd[x]=tt;
}
int fa[N],son[N],dep[N],siz[N];
void dfs1(int u){
	siz[u]=1;
	for(int i=hd[u];~i;i=e[i].nxt){
		int v=e[i].v;
		if(v==fa[u])
			continue;
		dep[v]=dep[u]+1;
		fa[v]=u;
		dfs1(v);
		siz[u]+=siz[v];
		if(dep[v]>dep[son[u]])
			son[u]=v;
	}
}
int top[N],rk[N],id[N],cnt;
void dfs2(int u,int t){
	top[u]=t;
	rk[u]=++cnt;
	id[cnt]=u;
	if(son[u])
		dfs2(son[u],t);
	for(int i=hd[u];~i;i=e[i].nxt){
		int v=e[i].v;
		if(v==fa[u]||v==son[u])
			continue;
		dfs2(v,v);
	}
}
struct node{
	int mx,mn,p,q;
};//p从左到右最大值,q从右到左最大值 
struct SGT{
	node tr[N<<2];
	int lz[N<<2];
	#define ls p<<1
	#define rs p<<1|1
	void change(int p,int v){
		tr[p].mn+=v;
		tr[p].mx+=v;
		lz[p]+=v;
	}
	node merge(node A,node B){
		node tmp;
		tmp.mx=max(A.mx,B.mx);
		tmp.mn=min(A.mn,B.mn);
		tmp.p=max(max(A.p,B.p),B.mx-A.mn);
		tmp.q=max(max(A.q,B.q),A.mx-B.mn);
		return tmp;
	}
	void spread(int p){
		if(lz[p]!=0){
			change(ls,lz[p]);
			change(rs,lz[p]);
			lz[p]=0;
		}
	}
	void build(int p,int l,int r){
		if(l==r){
			tr[p].mx=tr[p].mn=a[id[l]];
			return;
		}
		int mid=(l+r)>>1;
		build(ls,l,mid);
		build(rs,mid+1,r);
		tr[p]=merge(tr[ls],tr[rs]);
	}
	void update(int p,int l,int r,int L,int R,int v){
		if(L<=l&&R>=r){
			change(p,v);
			return;
		}
		spread(p);
		int mid=(l+r)>>1;
		if(L<=mid)
			update(ls,l,mid,L,R,v);
		if(R>mid)
			update(rs,mid+1,r,L,R,v);
		tr[p]=merge(tr[ls],tr[rs]);
	}
	node query(int p,int l,int r,int L,int R){
		if(L<=l&&R>=r)
			return tr[p];
		spread(p);
		int mid=(l+r)>>1;
		if(L<=mid&&R<=mid)
			return query(ls,l,mid,L,R);
		if(L>mid&&R>mid)
			return query(rs,mid+1,r,L,R);
		return merge(query(ls,l,mid,L,R),query(rs,mid+1,r,L,R));
	}
}T;
int way_query(int x,int y){
	node ans1,ans2; 
	ans1.p=ans1.q=0;
	ans1.mx=-INF;
	ans1.mn=INF;
	ans2=ans1;
	while(top[x]!=top[y]){
		if(dep[top[x]]<dep[top[y]]){
			node tmp=T.query(1,1,n,rk[top[y]],rk[y]);
			ans2.p=max(max(tmp.p,ans2.p),ans2.mx-tmp.mn);
			ans2.q=max(max(tmp.q,ans2.q),tmp.mx-ans2.mn);
			ans2.mx=max(ans2.mx,tmp.mx);
			ans2.mn=min(ans2.mn,tmp.mn);
			y=fa[top[y]];
		}
		else{
			node tmp=T.query(1,1,n,rk[top[x]],rk[x]);
			ans1.p=max(max(tmp.p,ans1.p),ans1.mx-tmp.mn);
			ans1.q=max(max(tmp.q,ans1.q),tmp.mx-ans1.mn);
			ans1.mx=max(ans1.mx,tmp.mx);
			ans1.mn=min(ans1.mn,tmp.mn);
			x=fa[top[x]];
		}
	}
	if(dep[x]<dep[y]){
		node tmp=T.query(1,1,n,rk[x],rk[y]);
		ans2.p=max(max(tmp.p,ans2.p),ans2.mx-tmp.mn);
		ans2.q=max(max(tmp.q,ans2.q),tmp.mx-ans2.mn);
		ans2.mx=max(ans2.mx,tmp.mx);
		ans2.mn=min(ans2.mn,tmp.mn);
	}
	else{
		node tmp=T.query(1,1,n,rk[y],rk[x]);
		ans1.p=max(max(tmp.p,ans1.p),ans1.mx-tmp.mn);
		ans1.q=max(max(tmp.q,ans1.q),tmp.mx-ans1.mn);
		ans1.mx=max(ans1.mx,tmp.mx);
		ans1.mn=min(ans1.mn,tmp.mn);
	}
	int res=max(max(ans1.q,ans2.p),ans2.mx-ans1.mn);
	if(res<=0)
		return 0;
	else
		return res;
}
void way_update(int x,int y,int v){
	while(top[x]!=top[y]){
		if(dep[top[x]]<dep[top[y]])
			swap(x,y);
		T.update(1,1,n,rk[top[x]],rk[x],v);
		x=fa[top[x]];
	}
	if(dep[x]>dep[y])
		swap(x,y);
	T.update(1,1,n,rk[x],rk[y],v);
}
signed main(){
	init();
	read(n);
	for(int i=1;i<=n;i++){
		read(a[i]);
	} 
	for(int i=1;i<n;i++){
		int x,y;
		read(x,y);
		add(x,y);
		add(y,x);
	}
	dfs1(1);
	dfs2(1,1);
	T.build(1,1,n);
	read(m);
	while(m--){
		int x,y,z;
		read(x,y,z);
		int tmp=way_query(x,y);
		write(tmp);
		putchar('\n');
		way_update(x,y,z);
	}
	return 0;
}
2024/8/6 19:07
加载中...