1020. Tree Traversals (25)

#define  _CRT_SECURE_NO_WARNINGS
#include<cstdio>
#include<cstring>
#include<cmath>
#include<string>
#include<vector>
#include<map>
#include<iostream>
#include<queue>
#include<algorithm>
using namespace std;


struct Node
{
int n;
Node *left, *right;
Node()
{
left = NULL; right = NULL;
}
};
int FindRoot(int root,int i,int j,vector<int>b)
{
int mark = i;
for (int k = i; k <= j; k++)
{
if (root == b[k])
{
mark = k;
return mark;
}
}
return mark;
}
Node* dealNode(vector<int>a, vector<int>b)
{ 
Node *root = new Node();
root->n = a[a.size()-1];
int k = FindRoot(a[a.size() - 1], 0, a.size() - 1,b);
vector<int>left_a, left_b, right_a, right_b;
for (int i = 0; i < k; i++)
{
left_b.push_back(b[i]);
left_a.push_back(a[i]);
}
for (int i = k + 1; i < b.size(); i++)
{
right_b.push_back(b[i]);
right_a.push_back(a[i - 1]);
}
if (left_b.size() > 0)
{
root->left = dealNode(left_a, left_b);
}
else
root->left = NULL;
if (right_b.size()>0)
{
root->right = dealNode(right_a, right_b);
}
else
root->right = NULL;
return root;
} 
int main()
{ 
int N = 0;
cin >> N;
int tmp;
vector<int>a;
vector<int>b;
for (int i = 0; i < N; i++)
{
cin >> tmp;
a.push_back(tmp);
}
for (int i = 0; i < N; i++)
{
cin >> tmp;
b.push_back(tmp);
}
Node *root = new Node();
root = dealNode(a,b);
queue<Node> vec;
vec.push(*root);
bool first = true;
while (vec.size() > 0)
{ 
Node n = vec.front();
if (first)
{
first = false;
cout << n.n;
}
else
cout << " " << n.n;
if (n.left != NULL)
vec.push(*n.left);
if (n.right != NULL)
vec.push(*n.right);
vec.pop();
}
return 0;
}