1127. ZigZagging on a Tree (30)

#include <iostream>
#include <vector>
using namespace std;
const int maxv=42;
int in[maxv],post[maxv],h=-1;
vector<int> v[maxv];
void Solve(int inL,int inR,int poL,int poR,int level)
{
if(inL>inR) return;
h=(h<level)?level:h;
v[level].push_back(post[poR]);
int e=post[poR],i=inL;
while(i<=inR&&e!=in[i]) ++i;
Solve(inL,i-1,poL,poL+i-1-inL,level+1);
Solve(i+1,inR,poL+i-inL,poR-1,level+1);
}
int main()
{
int n;
cin>>n;
for(int i=0;i<n;++i) cin>>in[i];
for(int i=0;i<n;++i) cin>>post[i];
Solve(0,n-1,0,n-1,1);
for(int i=1;i<=h;++i)
{
if(i&1)
for(auto it=v[i].rbegin();it!=v[i].rend();++it)
i==h&&it==v[i].rend()-1?cout<<*it:cout<<*it<<" ";
else
for(auto it=v[i].begin();it!=v[i].end();++it)
i==h&&it==v[i].end()-1?cout<<*it:cout<<*it<<" ";
}
return 0;
}