【BZOJ】【P1146】【CTSC2008】【网络管理Network】【题解】【整体二分+dfs序+树状数组】

传送门:http://www.lydsy.com/JudgeOnline/problem.php?id=1146

当年写的log^4n链剖树套树二分被log^2完虐http://blog.csdn.net/iamzky/article/details/24550247

这就是差距

Code:

#include<bits/stdc++.h>using namespace std;const int maxn=80005;vector<int>G[maxn];int n,m,siz[maxn],fa[maxn],top[maxn],dep[maxn],son[maxn],w[maxn],mp[maxn],z,L[maxn<<1],R[maxn<<1],tot;struct BIT{int d[maxn<<1];inline int lowbit(int x){return x&-x;}void updata(int x,int f){while(x<=tot)d[x]+=f,x+=lowbit(x);}int get(int x){int ans=0;while(x)ans+=d[x],x-=lowbit(x);return ans;}}T;int getint(){int res=0;char c=getchar();while(!isdigit(c))c=getchar();while(isdigit(c))res=res*10+c-'0',c=getchar();return res;}void dfs(int u){L[u]=++tot;siz[u]=1;for(int i=0;i<G[u].size();i++){int v=G[u][i];if(v!=fa[u]){fa[v]=u;dep[v]=dep[u]+1;dfs(v);siz[u]+=siz[v];if(siz[son[u]]<siz[v])son[u]=v;}}R[u]=++tot;}void build(int u,int tp){mp[u]=++z;top[u]=tp;if(son[u])build(son[u],tp);for(int i=0;i<G[u].size();i++){int v=G[u][i];if(v!=fa[u]&&v!=son[u])build(v,v);}}int lca(int u,int v){while(top[u]!=top[v]){if(dep[top[u]]<dep[top[v]])swap(u,v);u=fa[top[u]];}return dep[u]<dep[v]?u:v;}int count(int u,int v){int ans=0;while(top[u]!=top[v]){if(dep[top[u]]<dep[top[v]])swap(u,v);ans+=abs(dep[u]-dep[fa[top[u]]]);u=fa[top[u]];}return ans+abs(dep[u]-dep[v])+1;}struct qes{int x,y,z,ty,delta,cur,id;qes(int _x=0,int _y=0,int _z=0,int _ty=0,int _delta=0,int _cur=0,int _id=0):x(_x),y(_y),z(_z),ty(_ty),delta(_delta),cur(_cur),id(_id){};}q[maxn*3];//ty 1 insert 2 erase 3 queryint qsize,anss[maxn],mx,md,tmp[maxn];bool part(qes &Q){if(Q.ty==3){if(Q.delta+Q.cur>Q.z-1)return 1;Q.cur+=Q.delta;Q.delta=0;return 0;}return Q.y<=md;}void solve(int lef,int rig,int l,int r){if(l==r){for(int i=lef;i<=rig;i++)if(q[i].ty==3)anss[q[i].id]=q[i].z>0?l:-1;return;}int mid=(l+r)>>1;md=mid;for(int i=lef;i<=rig;i++){if(q[i].ty==1&&q[i].y<=mid)T.updata(L[q[i].x],1),T.updata(R[q[i].x],-1),tmp[q[i].x]++;if(q[i].ty==2&&q[i].y<=mid)T.updata(L[q[i].x],-1),T.updata(R[q[i].x],1),tmp[q[i].x]--;if(q[i].ty==3)q[i].delta=T.get(L[q[i].x])+T.get(L[q[i].y])-2*T.get(L[lca(q[i].x,q[i].y)])+tmp[lca(q[i].x,q[i].y)];}for(int i=lef;i<=rig;i++){if(q[i].ty==1&&q[i].y<=mid)T.updata(L[q[i].x],-1),T.updata(R[q[i].x],1),tmp[q[i].x]--;if(q[i].ty==2&&q[i].y<=mid)T.updata(L[q[i].x],1),T.updata(R[q[i].x],-1),tmp[q[i].x]++;}int dv=stable_partition(q+lef,q+rig+1,part)-q-1;     if(lef<=dv)solve(lef,dv,l,mid);  if(dv+1<=rig)    solve(dv+1,rig,mid+1,r);  }int main(){n=getint();m=getint();for(int i=1;i<=n;i++){w[i]=getint();mx=max(mx,w[i]);q[++qsize]=qes(i,w[i],0,1);}for(int i=1;i<n;i++){int u=getint(),v=getint();G[u].push_back(v);G[v].push_back(u);}int root=1;//(n+1)>>1;dfs(root);build(root,root);for(int i=1;i<=m;i++){int k=getint(),a=getint(),b=getint();if(k==0){q[++qsize]=qes(a,w[a],0,2);q[++qsize]=qes(a,w[a]=b,0,1);mx=max(mx,w[a]);}else{int x=count(a,b);k=x-k+1;q[++qsize]=qes(a,b,k,3,0,0,++anss[0]);}}solve(1,qsize,0,mx);for(int i=1;i<=anss[0];i++)if(~anss[i])printf("%d\n",anss[i]);else puts("invalid request!");return 0;}