标签：ace cat HERE key color tree tle line number
Suppose that all the keys in a binary tree are distinct positive integers. Given the postorder and inorder traversal sequences, you are supposed to output the level order traversal sequence of the corresponding binary tree.
Input Specification:
Each input file contains one test case. For each case, the first line gives a positive integer N (<=30), the total number of nodes in the binary tree. The second line gives the postorder sequence and the third line gives the inorder sequence. All the numbers in a line are separated by a space.
Output Specification:
For each test case, print in one line the level order traversal sequence of the corresponding binary tree. All the numbers in a line must be separated by exactly one space, and there must be no extra space at the end of the line.
Sample Input:
7
2 3 1 5 7 6 4
1 2 3 4 5 6 7Sample Output:
4 1 6 3 5 7 2
C++代码如下：
1 #include<iostream> 2 #include<queue> 3 using namespace std; 4 5 6 struct node { 7 int data; 8 node *lchild, *rchild; 9 }; 10 11 int post[35], in[35]; 12 int n; 13 14 node* create(int posL,int posR,int inL,int inR) { 15 if (posL>posR) return NULL; 16 node *root = new node; 17 root->data = post[posR]; 18 int k; 19 for (k = inL; k <=inR; k++) { 20 if (in[k] == post[posR]) break; 21 } 22 int numL = k-inL; 23 root->lchild = create(posL, posL + numL-1, inL, k - 1); 24 root->rchild = create(posL + numL, posR - 1, k + 1, inR); 25 26 return root; 27 } 28 29 int num = 0; 30 31 void level(node*r) { 32 if (r == NULL) return; 33 queue<node*>q; 34 q.push(r); 35 while (!q.empty()) { 36 node *top = q.front(); 37 q.pop(); 38 num++; 39 cout << top->data; 40 if (num < n) cout << ‘ ‘; 41 if (top->lchild != NULL) q.push(top->lchild); 42 if (top->rchild != NULL) q.push(top->rchild); 43 } 44 } 45 46 int main() { 47 cin >> n; 48 int t; 49 for (int i = 0; i < n; i++) { 50 cin >> t; 51 post[i] = t; 52 } 53 for (int i = 0; i < n; i++) { 54 cin >> t; 55 in[i] = t; 56 } 57 node*root = create(0, n - 1, 0, n - 1); 58 level(root); 59 return 0; 60 }
【PAT】1020 Tree Traversals (25)（25 分）
标签：ace cat HERE key color tree tle line number
原文地址：https://www.cnblogs.com/pgzhang/p/9532042.html
