Populating Next Right Pointers in Each Node

 1     //按说层次遍历最方便了，但是空间复杂度不满足题意
    //遍历吧，可是像例子中的，5—>6怎么实现呢
    //You may assume that it is a perfect binary tree (ie, all leaves are at the same level, and every parent has two children).
    //这个提示是什么意思？
    void connect(TreeLinkNode *root) {
        if(root==NULL)
            return;
        if(root->left)
            root->left->next=root->right;
        if(root->next&&root->right)
            root->right->next=root->next->left;
        connect(root->left);
        connect(root->right);
        //Initially, all next pointers are set to NULL.因为这句话，所以根节点的next和最右结点的next就不用指定为NULL啦
    }

AC

参看http://blog.csdn.net/fightforyourdream/article/details/14514165