靈魂代碼=。=終於改出來了
#include<stdio.h>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<string>
#include<set>
#include<queue>
#include<vector>
using namespace std;
typedef long long ll;
struct node
{
int l,r;
} tree[100005];
int a[100005],b[100005];
int build(int la,int ra,int lb,int rb)//通過中序 (先序)後序建樹
{
if(la>ra)
return 0;
int rt=a[rb];//中序後序
//int rt=a[lb];//中序先序
int p1=la;
while(b[p1]!=rt)
p1++;
int p2=p1-la;//前半部分是lb->lb+p2 後半部分lb+p2->rb
tree[rt].l=build(la,p1-1,lb,lb+p2-1);//中序後序
tree[rt].r=build(p1+1,ra,lb+p2,rb-1);
//tree[rt].l=build(la,p1-1,lb+1,lb+p2);//中序先序
//tree[rt].r=build(p1+1,ra,lb+p2+1,rb);
return rt;
}
void bfs(int x)
{
vector<int>v;
queue<int>q;
q.push(x);
while(!q.empty())
{
int u=q.front();
q.pop();
if(u==0)
break;
v.push_back(u);
if(tree[u].l!=0)
q.push(tree[u].l);
if(tree[u].r!=0)
q.push(tree[u].r);
}
int l=v.size();
for(int i=0; i<l-1; i++)
{
printf("%d ",v[i]);
}
printf("%d\n",v[l-1]);
}
int main()
{
int n;
cin>>n;
for(int i=1; i<=n; i++)
cin>>a[i];
for(int i=1; i<=n; i++)
cin>>b[i];
build(1,n,1,n);
bfs(a[n]);//中序後序
//bfs(a[1]);//中序先序
}