【BZOJ3545】 [ONTAK2010]Peaks

BZOJ3545 [ONTAK2010]Peaks

---

Solution

既然会加强版,直接把强制在线的操作去掉就好了.

代码实现

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<math.h>
#include<algorithm>
#include<queue>
#include<set>
#include<map>
#include<iostream>
using namespace std;
#define ll long long
#define re register
#define file(a) freopen(a".in","r",stdin);freopen(a".out","w",stdout)
inline int gi(){
	int f=1,sum=0;char ch=getchar();
	while(ch>'9' || ch<'0'){if(ch=='-')f=-1;ch=getchar();}
	while(ch>='0' && ch<='9'){sum=(sum<<3)+(sum<<1)+ch-'0';ch=getchar();}
	return f*sum;
}
int two[20];
int n,m,Q,cnt,top,tot,nodes,lastans;
int H[100005],h[100005];
int f[200005],val[200005],st[200005],ed[200005];
int q[300005],rt[300005];
int ls[5000005],rs[5000005],sum[5000005];
int dep[200005],fa[200005][17],mx[200005][17];
bool vis[200005];
struct node{int u,v,w;}e[500005];
int to[200005],nxt[200005],front[200005];
bool operator<(node a,node b){
	return a.w<b.w;
}
inline void Add(int u,int v){
	to[++cnt]=v;nxt[cnt]=front[u];front[u]=cnt;
}
inline int find(int x){
	if(f[x]!=x)f[x]=find(f[x]);
	return f[x];
}
inline int Find(int x,int val){
	for(int i=17;~i;i--)
		if(dep[x]>=two[i] && mx[x][i]<=val)x=fa[x][i];
	return x;
}
inline void insert(int l,int r,int &x,int f,int val){
	x=++tot;
	sum[x]=sum[f]+1;
	if(l==r)return;
	ls[x]=ls[f];rs[x]=rs[f];
	int mid=(l+r)>>1;
	if(val<=mid)insert(l,mid,ls[x],ls[f],val);
	else insert(mid+1,r,rs[x],rs[f],val);
}
inline int query(int l,int r,int x,int y,int rank){
	if(l==r)return l;
	int mid=(l+r)>>1;
	if(sum[ls[y]]-sum[ls[x]]>=rank)return query(l,mid,ls[x],ls[y],rank);
	else return query(mid+1,r,rs[x],rs[y],rank-sum[ls[y]]+sum[ls[x]]);
}
inline void dfs(int u){
	vis[u]=1;q[++top]=u;
	for(int i=1;i<=16;i++)
		if(dep[u]>=two[i]){
			fa[u][i]=fa[fa[u][i-1]][i-1];
			mx[u][i]=max(mx[u][i-1],mx[fa[u][i-1]][i-1]);
		}
		else break;
	for(int i=front[u];i;i=nxt[i]){
		int v=to[i];
		dep[v]=dep[u]+1;
		mx[v][0]=val[u];
		fa[v][0]=u;
		dfs(v);
	}
	if(u>n)q[++top]=u;
}
inline void solve(){
	for(re int i=1;i<=Q;i++){
		re int v=gi(),x=gi(),k=gi();
//		if(lastans!=-1)v^=lastans,x^=lastans,k^=lastans;
		re int t=Find(v,x);
		re int a=rt[st[t]],b=rt[ed[t]];
		if(sum[b]-sum[a]<k)lastans=-1;
		else lastans=H[query(1,n,a,b,sum[b]-sum[a]-k+1)];
		printf("%d
",lastans);
	}
}
int main()
{
	two[0]=1;
	for(re int i=1;i<20;i++)two[i]=two[i-1]<<1;
	n=gi();m=gi();Q=gi();
	for(re int i=1;i<=n;i++)h[i]=gi(),H[i]=h[i];
	sort(H+1,H+n+1);
	for(re int i=1;i<=n;i++)h[i]=lower_bound(H+1,H+n+1,h[i])-H;
	for(re int i=1;i<=n+n;i++)f[i]=i;
	for(re int i=1;i<=m;i++)
		e[i].u=gi(),e[i].v=gi(),e[i].w=gi();
	sort(e+1,e+m+1);
	nodes=n;
	for(re int i=1;i<=m;i++){
		re int u=find(e[i].u),v=find(e[i].v);
		if(u!=v){
			nodes++;
			f[u]=f[v]=nodes;
			val[nodes]=e[i].w;
			Add(nodes,u);Add(nodes,v);
			if(nodes==2*n-1)break;
		}
	}
	for(re int i=1;i<=n;i++)
		if(!vis[i])dfs(find(i));
	for(re int i=1;i<=top;i++){
		re int t=q[i];
		if(t<=n)insert(1,n,rt[i],rt[i-1],h[t]);
		else{
			rt[i]=rt[i-1];
			if(!st[t])st[t]=i;
			else ed[t]=i;
		}
	}
	solve();
	return 0;
}