/** * Definition for binary tree with next pointer. * struct TreeLinkNode { *  int val; *  TreeLinkNode *left, *right, *next; *  TreeLinkNode(int x) : val(x), left(NULL), right(NULL), next(NULL) {} * }; */ /* 给二叉树的每个节点加一个Next指针，使得每个节点指向它的相连节点，如果该指针没有相连节点next就指向NULL 暴力写了一下，也过了 */class Solution {public:    void dfs(TreeLinkNode *root1,TreeLinkNode *root2){        if(!root1||!root2||root1->next!=NULL) return;        root1->next = root2;        dfs(root1->left,root1->right);        dfs(root1->right,root2->left);        dfs(root2->left,root2->right);        dfs(root2->right,root2->next);    }    void connect(TreeLinkNode *root) {        if(!root) return ;        root->next = NULL;        dfs(root->left,root->right);        dfs(root->right,root->next);    }};

 

/** * Definition for binary tree with next pointer. * struct TreeLinkNode { *  int val; *  TreeLinkNode *left, *right, *next; *  TreeLinkNode(int x) : val(x), left(NULL), right(NULL), next(NULL) {} * }; */ /*简洁版的 */class Solution {public:    void dfs(TreeLinkNode *root){        if(!root||!root->left) return;        root->left->next = root->right;        root->right->next = (root->next)?root->next->left:NULL;        dfs(root->left);        dfs(root->right);    }    void connect(TreeLinkNode *root) {        dfs(root);    }};