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; }