rand.cpp
#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
int main()
{
freopen("q.in","w",stdout);
srand(time(0));
int n=rand()%200+1,m=rand()%200+1;
cout<<n<<endl;
for(int i=2;i<=n;i++){
int u=rand()%i+1;
if(u==i)u--;
cout<<i<<' '<<u<<endl;
}
cout<<m<<endl;
for(int i=1;i<=m;i++){
int p=rand()%2;
if(p){
cout<<'C'<<' '<<rand()%n+1<<endl;
}
else cout<<'G'<<endl;
}
}
dp.cpp
#include<bits/stdc++.h>
using namespace std;
int cnt,n;
int main()
{
// cin>>n;
n=100;
for(int i=1;i<=n;i++){
cout<<i<<" ";
system("./rand; ./a; ./q");
if(system("diff q.out std.out")){
puts("WA");
return 0;
}
printf("AC\n");
}
}
q.cpp
#include<bits/stdc++.h>
using namespace std;
const int N=5e5+100;
int n,m,a,b,cnt,head[N],maxn[N],siz[N],sum,root,rt;
char ch;
int num,fa[N],d[N],id[N],c,depth[N];
bool black[N],vis[N];
int _siz[N],_son[N],dad[N],top[N];
int t[N*20],tot,rrt[N],chi[N*20][2],rd[N*20],sz[N*20],xr[N*20],fir[N],sec[N];
struct edge{
int to,nxt;
}e[N<<1];
vector<int>v[N];
vector<int>son[N];
struct Treap{
int add(int x){
tot++;
t[tot]=x;
sz[tot]=xr[tot]=1;
rd[tot]=rand();
return tot;
}
void up(int r){
sz[r]=sz[chi[r][0]]+sz[chi[r][1]]+xr[r];
}
void rotate(int &r,int d){
int x=chi[r][d];
chi[r][d]=chi[x][d^1];
chi[x][d^1]=r;
up(r);
r=x;
up(r);
}
void insert(int &r,int x){
if(!r){
r=add(x);
return ;
}
sz[r]++;
if(t[r]==x){
xr[r]++;
return ;
}
int d=(x>t[r]);
insert(chi[r][d],x);
if(rd[chi[r][d]]>rd[r])rotate(r,d);
}
void erase(int &r,int x){
if(!r)return ;
if(t[r]==x){
if(xr[r]>1){
xr[r]--;
sz[r]--;
return ;
}
if(!chi[r][0]||!chi[r][1])r=chi[r][0]+chi[r][1];
else {
int d=(rd[chi[r][0]]<rd[chi[r][1]]);
rotate(r,d);
erase(r,x);
}
}
else {
sz[r]--;
erase(chi[r][t[r]<x],x);
}
}
int find(int r,int x){
if(!r)return 0;
if(sz[chi[r][0]]>=x)return find(chi[r][0],x);
else if(sz[chi[r][0]]+xr[r]>=x)return t[r];
else return find(chi[r][1],x-sz[chi[r][0]]-xr[r]);
}
}s[N],et[N];
void add_edge(int u,int v){
cnt++;
e[cnt].to=v;
e[cnt].nxt=head[u];
head[u]=cnt;
}
void dfs1(int u,int f){
_siz[u]=1;
dad[u]=f;
depth[u]=depth[f]+1;
for(int i=head[u];i;i=e[i].nxt){
int v=e[i].to;
if(v==f)continue;
dfs1(v,u);
if(_siz[v]>_siz[_son[u]])_son[u]=v;
_siz[u]+=_siz[v];
}
}
void dfs2(int u,int t){
top[u]=t;
if(_son[u])dfs2(_son[u],t);
for(int i=head[u];i;i=e[i].nxt){
int v=e[i].to;
if(v==dad[u]||v==_son[u])continue;
dfs2(v,v);
}
}
int LCA(int x,int y){
int fx=top[x],fy=top[y];
while(fx!=fy){
if(depth[fx]<depth[fy]){
swap(x,y);
swap(fx,fy);
}
x=dad[fx];
fx=top[x];
}
if(depth[x]>depth[y])return y;
else return x;
}
void getroot(int u,int f){
maxn[u]=0;
siz[u]=1;
for(int i=head[u];i;i=e[i].nxt){
int v=e[i].to;
if(v==f||vis[v])continue;
getroot(v,u);
siz[u]+=siz[v];
maxn[u]=max(maxn[u],siz[v]);
}
maxn[u]=max(maxn[u],sum-siz[u]);
if(maxn[u]<maxn[root])root=u;
}
void init(int u,int f,int an){
s[an].insert(rrt[an],depth[fa[an]]+depth[u]-2*depth[LCA(fa[an],u)]);
for(int i=head[u];i;i=e[i].nxt){
int v=e[i].to;
if(vis[v]||v==f)continue;
init(v,u,an);
}
}
void dfs(int u,int f){
vis[u]=1;
fa[u]=f;
init(u,f,u);
for(int i=head[u];i;i=e[i].nxt){
int v=e[i].to;
if(vis[v])continue;
root=0;sum=siz[v];
getroot(v,u);
son[u].push_back(root);
dfs(root,u);
}
et[u].insert(rrt[u+n],0);
for(auto v:son[u]){
et[u].insert(rrt[u+n],s[v].find(rrt[v],sz[rrt[v]]));
}
}
void updata(int u,int v,bool pd){
if(pd==0){
while(u){
int lca=LCA(fa[u],v),ddd=depth[fa[u]]+depth[v]-2*depth[lca];
s[u].erase(rrt[u],ddd);
if(sz[rrt[u]]){
int _=s[u].find(rrt[u],sz[rrt[u]]);
if(ddd>_){
et[fa[u]].erase(rrt[fa[u]+n],ddd);
et[fa[u]].insert(rrt[fa[u]+n],_);
}
}
else et[fa[u]].erase(rrt[fa[u]+n],ddd);
u=fa[u];
if(fa[u]==u)return ;
}
}
else{
while(u){
int lca=LCA(fa[u],v),ddd=depth[fa[u]]+depth[v]-2*depth[lca];
if(sz[rrt[u]]){
int _=s[u].find(rrt[u],sz[rrt[u]]);
if(ddd>_){
et[fa[u]].erase(rrt[fa[u]+n],_);
et[fa[u]].insert(rrt[fa[u]+n],ddd);
}
}
else et[fa[u]].insert(rrt[fa[u]+n],ddd);
s[u].insert(rrt[u],ddd);
if(fa[u]==u)return ;
u=fa[u];
}
}
}
int main()
{
// freopen("q.in","r",stdin);
// freopen("q.out","w",stdout);
srand(time(0));
scanf("%d",&n);
for(int i=1;i<n;i++){
scanf("%d%d",&a,&b);
add_edge(a,b);
add_edge(b,a);
}
num=n;
for(int i=1;i<=n;i++){
black[i]=1;
}
root=0;c=n;
maxn[0]=n+1;
sum=n;
getroot(1,0);rt=root;
dfs1(root,0);
dfs2(root,root);
dfs(root,root);
// for(int i=1;i<=n;i++){
// cout<<i<<':';
// for(int j=1;j<=sz[rrt[i+n]];j++){
// cout<<et[i].find(rrt[i+n],j)<<' ';
// }
// puts("");
// }
scanf("%d",&m);
while(m--){
cin>>ch;
if(ch=='G'){
if(num==0)puts("-1");
else if(num==1)puts("0");
else {
printf("%d\n",et[rt].find(rrt[rt+n],sz[rrt[rt+n]])+et[rt].find(rrt[rt+n],sz[rrt[rt+n]]-1));
}
}
else{
scanf("%d",&a);
if(black[a]){
num--;
updata(a,a,0);
}
else{
num++;
updata(a,a,1);
}
black[a]^=1;
}
}
}
std.cpp
#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<queue>
using namespace std;
const int N=200100;
struct que{
priority_queue<int> x,y;
inline void push(int a){x.push(a);}
inline void del(int a){y.push(a);}
inline int top(){while(y.size()&&x.top()==y.top())x.pop(),y.pop();return x.top();}
inline int size(){return x.size()-y.size();}
inline void pop(){while(y.size()&&x.top()==y.top())x.pop(),y.pop();x.pop();}
inline int sectop(){int a=top();pop();int b=top();push(a);return b;}
}A,B[N],C[N];
int cnt,head[N];
int light[N],tot,n,m;
int root,size[N],g[N],vis[N],all,f[N];
int dep[N],mn[N*2][24],num,dfn[N];
int Log[N];
struct edge{
int to,nxt;
}e[N*2];
inline void add_edge(int u,int v){
cnt++;
e[cnt].nxt=head[u];
e[cnt].to=v;
head[u]=cnt;
}
inline void dfs(int u,int f){
dfn[u]=++num;
dep[u]=dep[f]+1;
mn[num][0]=dep[u];
for(int i=head[u];i;i=e[i].nxt){
int v=e[i].to;
if(v==f)continue;
dfs(v,u);
mn[++num][0]=dep[u];
}
}
inline void getroot(int u,int f){
g[u]=0;size[u]=1;
for(int i=head[u];i;i=e[i].nxt){
int v=e[i].to;
if(v==f||vis[v])continue;
getroot(v,u);
g[u]=max(g[u],size[v]);
size[u]+=size[v];
}
g[u]=max(g[u],all-size[u]);
if(g[u]<g[root])root=u;
}
inline int getdep(int x,int y){
int a=dfn[x];
int b=dfn[y];
if(a>b)swap(a,b);
int len=Log[b-a+1];
return min(mn[a][len],mn[b-(1<<len)+1][len]);
}
inline int dis(int x,int y){
return dep[x]+dep[y]-2*getdep(x,y);
}
inline void work(int u,int ff){
C[root].push(dis(u,f[root]));
size[u]=1;
for(int i=head[u];i;i=e[i].nxt){
int v=e[i].to;
if(v==ff||vis[v])continue;
work(v,u);
size[u]+=size[v];
}
}
inline void pusha(int x){
if(B[x].size()>=2)A.push(B[x].top()+B[x].sectop());
}
inline void dela(int x){
if(B[x].size()>=2)A.del(B[x].top()+B[x].sectop());
}
inline void build(int u,int ff){
f[u]=ff;vis[u]=1;
B[u].push(0);
work(u,0);
for(int i=head[u];i;i=e[i].nxt){
int v=e[i].to;
if(vis[v])continue;
root=0,all=size[v];
getroot(v,0);
v=root;
build(root,u);
B[u].push(C[v].top());
}
pusha(u);
}
inline void on(int x){
dela(x);
B[x].del(0);
pusha(x);
for(int i=x;f[i];i=f[i]){
dela(f[i]);
B[f[i]].del(C[i].top());
C[i].del(dis(x,f[i]));
if(C[i].size())B[f[i]].push(C[i].top());
pusha(f[i]);
}
}
inline void off(int x){
dela(x);
B[x].push(0);
pusha(x);
for(int i=x;f[i];i=f[i]){
dela(f[i]);
if(C[i].size())B[f[i]].del(C[i].top());
C[i].push(dis(x,f[i]));
B[f[i]].push(C[i].top());
pusha(f[i]);
}
}
void prework(){
for(int j=1;j<=Log[num];j++)
for(int i=1;i+(1<<j)-1<=num;i++)
mn[i][j]=min(mn[i][j-1],mn[i+(1<<(j-1))][j-1]);
}
inline int read(){
int sum=0,f=1;char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9'){sum=sum*10+ch-'0';ch=getchar();}
return sum*f;
}
int main(){
freopen("q.in","r",stdin);
freopen("std.out","w",stdout);
n=read();
Log[0]=-1;for(int i=1;i<=200000;i++)Log[i]=Log[i>>1]+1;
for(int i=1;i<n;i++){
int u=read(),v=read();
add_edge(u,v);add_edge(v,u);
}
dfs(1,0);
prework();
g[0]=n;root=0;all=n;
getroot(1,0);
build(root,0);
tot=n;
m=read();
char s;
while(m--){
cin>>s;
if(s=='G'){
if(tot<=1)printf("%d\n",tot-1);
else printf("%d\n",A.top());
}
else{
int x=read();
if(light[x]==0)on(x),tot--;
else off(x),tot++;
light[x]^=1;
}
}
return 0;
}
