pat1191119. Pre- and Post-order Traversals

原创文章using namespace std;#include <iostream>#include <vector>void dfs(vector<int>&preorder, vector<int>&postorder, vector<int>&inorder,bool&flag, int l1, int r1, int l2, int r2){  if (l1 == r1)  {    inorder.push_back(preorder[l1]);    return;  }  int index = -1;  for (int i = l1 + 1; i <= r1; i++)  {    if (preorder[i] == postorder[r2 - 1])    {      index = i;    break;    }  }  if(preorder[l1 + 1] == postorder[r2 - 1])  {    flag = false;    dfs(preorder, postorder, inorder, flag,l1+ 1, r1, l2,r2 - 1);    inorder.push_back(preorder[l1]);  }else  {  dfs(preorder, postorder, inorder, flag,l1+ 1, index - 1, l2,l2 + index - 1 - l1 - 1);  inorder.push_back(preorder[l1]);  dfs(preorder, postorder, inorder, flag, index, r1, r2 - 1 - r1 + index,r2 - 1);  }}int main(){  int N;  cin >> N;  vector<int> pre(N,0);  vector<int> post(N,0);  for (int i = 0; i < N; i++)  {    cin >> pre[i];  }  for (int i = 0; i < N; i++)  {    cin >> post[i];  }  vector<int> inorder;  bool flag = true;  dfs(pre, post, inorder, flag, 0, N - 1, 0, N - 1);  if (flag)  {    cout << "Yes" << endl;  }  else  {    cout << "No" << endl;  }  for (int i = 0; i < N; i++)  {    if (i == 0)    {      cout << inorder[i];      continue;    }    cout << " " << inorder[i];  }  cout << endl;  }