标签：
反转二叉树就是左右节点互换
层遍历使用队列实现
中序遍历递归实现
The following is from Max Howell @twitter:
Google: 90% of our engineers use the software you wrote (Homebrew), but you can‘t invert a binary tree on a whiteboard so fuck off.
Now it‘s your turn to prove that YOU CAN invert a binary tree!
Input Specification:
Each input file contains one test case. For each case, the first line gives a positive integer N (<=10) which is the total number of nodes in the tree -- and hence the nodes are numbered from 0 to N-1. Then N lines follow, each corresponds to a node from 0 to N-1, and gives the indices of the left and right children of the node. If the child does not exist, a "-" will be put at the position. Any pair of children are separated by a space.
Output Specification:
For each test case, print in the first line the level-order, and then in the second line the in-order traversal sequences of the inverted tree. There must be exactly one space between any adjacent numbers, and no extra space at the end of the line.
Sample Input:8 1 - - - 0 - 2 7 - - - - 5 - 4 6Sample Output:
3 7 2 6 4 0 5 1 6 5 7 4 3 2 0 1
#include <iostream>#include <queue>using namespace std;int n;int lfchild[10] = { -1 };int richild[10] = { -1 };queue<int> tree;int cnt = 0;void Inorder(int a) {if (lfchild[a] != -1)Inorder(lfchild[a]);cout << a;cnt++;if (cnt < n)cout << " ";if (richild[a] != -1)Inorder(richild[a]);}int main(void) {for (int i = 0; i < 10; i++) {lfchild[i] = -1;richild[i] = -1;}int mark[10] = { 0 };cin >> n;for (int i = 0; i < n; i++) {char l, r;cin >> l >> r;if (l != ‘-‘) {richild[i] = l - ‘0‘;mark[l - ‘0‘]++;}if (r != ‘-‘) {lfchild[i] = r - ‘0‘;mark[r - ‘0‘]++;}}int root = 0;for (int i = 0; i < n; i++) {if (mark[i] == 0) {root = i;break;}}tree.push(root);while (tree.size()>0){if (lfchild[tree.front()] != -1) {tree.push(lfchild[tree.front()]);}if (richild[tree.front()] != -1) {tree.push(richild[tree.front()]);}cout << tree.front();tree.pop();if (tree.size() != 0)cout << " ";}cout << endl;Inorder(root);return 0;}
1102. Invert a Binary Tree (25)
标签：
原文地址：http://www.cnblogs.com/zzandliz/p/5023353.html
