剑指offer之二叉树镜像

1.二叉树镜像是指左右对换一个二叉树

         1      /   \     2     4    /      /   3       5

变成

         1      /   \     4     2      \     \       5     3

递归交换非叶子节点左右子树即可

2.代码

#include<stdio.h>#include<stack>struct BinaryTree{    int value;    BinaryTree* left;    BinaryTree* right;};void mirrorTreeDFS(BinaryTree* root){    if(root==NULL || (root->left==NULL && root->right==NULL))        return;    BinaryTree *tmp = root->left;    root->left = root->right;    root->right = tmp;    if(root->left)        mirrorTreeDFS(root->left);    if(root->right)        mirrorTreeDFS(root->right);}void mirrorTree(BinaryTree* root){    if(root==NULL || (root->left==NULL && root->right==NULL))        return;    std::stack nodeStack;    nodeStack.push(root);    while(nodeStack.size() > 0)    {        BinaryTree* cur = nodeStack.top();        nodeStack.pop();        BinaryTree* tmp = cur->left;        cur->left = cur->right;        cur->right = tmp;        if(cur->left)            nodeStack.push(cur->left);        if(cur->right)            nodeStack.push(cur->right);    }}