80分代码
17~21点权为1时被卡了
```cpp
#include<bits/stdc++.h>
using namespace std;
int n,d[1000005],point[1000005],lch[1000005],rch[1000005],maxn=1,bj;
vector<int>vec;
vector<int>::iterator it;
void INIT(int x)
{ if(lch[x]!=-1){
INIT(lch[x]);
point[x]+=point[lch[x]];
}
if(rch[x]!=-1){
INIT(rch[x]);
point[x]+=point[rch[x]];
}
point[x]++;
}
void check(int x){
if(lch[x]==-1||rch[x]==-1)return;
check(lch[x]);
check(rch[x]);
if(d[lch[x]]!=d[rch[x]])bj=0;
}
int main()
{ scanf("%d",&n);
for(int i=1;i<=n;i++)scanf("%d",&d[i]);
for(int i=1;i<=n;i++)scanf("%d%d",&lch[i],&rch[i]);
INIT(1);
for(int i=1;i<=n;i++)
if(lch[i]!=-1&&rch[i]!=-1)
if(point[lch[i]]==point[rch[i]])vec.push_back(i);
for(it=vec.begin();it!=vec.end();it++){
bj=1;
check(*it);
if(bj)maxn=max(maxn,point[*it]);
}
cout<<maxn<<endl;
return 0;
}
```
但理论上这份代码是错的，~~由此可见民间数据有多水~~
by Soledad_S @ 2018-11-11 09:53:35
```pascal
begin
write('1');
end.
```
我的打表40分。。。
by xujian @ 2018-11-11 10:00:26
更正，是24分
by xujian @ 2018-11-11 10:00:47
唉，我~~太弱了~~
by xujian @ 2018-11-11 10:01:03
@[longlongzhu123](/space/show?uid=57525) 可以
```
#include<iostream>
#include<cstdio>
using namespace std;
#define ll long long
struct twree{
ll left,right,num;
};
twree a[2300003];
ll n;
ll check;
ll ans=1;
ll sum=1;
ll read() {
ll x=0,f=1;
char ch=getchar() ;
while(ch<'0'||ch>'9') {
if(ch=='-') f=-f;
ch=getchar();
}
while(ch>='0'&&ch<='9') {
x=x*10+ch-'0';
ch=getchar();
}
return x*f;
}
void dfs(ll x,ll y) {
if(a[x].num==-1&&a[y].num==-1) {
return ;
}
else if(a[x].num==a[y].num) {
sum+=2;
}
else if(a[x].num!=-1||a[y].num!=-1) {
sum=1;
check=1;
return ;
}
else if(a[x].right!=-1||a[y].left!=-1||a[y].right!=-1||a[x].left!=-1) {
//cout<<sum<<endl;
sum=1;
check=1;
return ;
}
//cout<<a[x].left<<" "<<a[y].right<<" "<<sum<<endl;
if(a[x].right==-1&&a[y].left!=-1) {
sum=1;
check=1;
return ;
}
if(a[x].left==-1&&a[y].right!=-1) {
sum=1;
check=1;
return ;
}
if(a[y].left==-1&&a[x].right!=-1) {
//cout<<a[x].left<<" "<<a[y].right<<" "<<sum<<endl;
sum=1;
check=1;
return ;
}
if(a[y].right==-1&&a[x].left!=-1) {
sum=1;
check=1;
return ;
}
if(a[x].right!=-1&&a[y].left!=-1) {
//cout<<x<<" "<<y<<" "<<a[x].right<<" "<<a[y].left<<endl;
dfs(a[x].right,a[y].left);
}
if(a[y].right!=-1&&a[x].left!=-1) {
//cout<<x<<" "<<y<<" "<<a[x].left<<" "<<a[y].right<<endl;
dfs(a[x].left,a[y].right);
}
if(a[x].left==-1&&a[x].right==-1) return ;
if(a[y].left==-1&&a[y].right==-1) return ;
}
int main() {
n=read();
/*if(n==1) {
cout<<n;
return 0;
}*/
for(ll i=1;i<=n;i++) {
a[i].num=read();
}
for(ll i=1;i<=n;i++) {
a[i].left=read();
a[i].right=read();
}
for(ll i=1;i<=n;i++) {
if(a[i].left==-1||a[i].right==-1) continue;
if(a[a[i].left].num!=a[a[i].right].num) continue;
dfs(a[i].left,a[i].right);
if(check==1) {
check=0;
continue;
}
ans=max(ans,sum);
sum=1;
}
cout<<ans<<endl;
return 0;
}
```
by 任弈凡 @ 2018-11-27 13:38:21
纯暴力
by 任弈凡 @ 2018-11-27 13:38:36