leetcode 代码实现详解

class Solution {
public:
 typedef TreeLinkNode * Snode;

    void connect(TreeLinkNode *root) {

       if(root == NULL)
     return ;
       root->next = NULL;
    if(root->left != NULL && root->right != NULL)
      root->left->next = root->right;
    TreeLinkNode parent(0);
    parent.left = root;
    rconnect(root,&parent);

  
    }
 void rconnect(TreeLinkNode *root,TreeLinkNode *parentroot)
 {
     connecthlevel(root,parentroot);

     pair<Snode,Snode> temp;
  temp=getfirst(parentroot);
     if(temp.first == NULL)
   return ;
         
       rconnect(temp.first,temp.second);
  
 }
 pair<Snode,Snode> getfirst(TreeLinkNode *parentroot)
    {
       TreeLinkNode *ptemp = NULL;
       while(parentroot != NULL)
       {
       
        if(parentroot->left != NULL)
        {
           ptemp = parentroot->left;
     if(ptemp->left != NULL)
     {
           return pair<Snode,Snode>(ptemp->left,ptemp);
     }
        if(ptemp->right != NULL)
        {
              return pair<Snode,Snode>(ptemp->right,ptemp);
     
        } 
 
  }
     if(parentroot->right != NULL)
     {
   ptemp = parentroot->right;
   if(ptemp->left != NULL)
      {
      return pair<Snode,Snode>(ptemp->left,ptemp);
      }
      if(ptemp->right != NULL)
      {
     return pair<Snode,Snode>(ptemp->right,ptemp);
      }   
   
  }
  parentroot = parentroot->next;
    }
    ptemp = NULL;
    return pair<Snode,Snode>(ptemp,ptemp);

 }
 void connecthlevel(TreeLinkNode *root,TreeLinkNode *parentroot)
 {
        if(parentroot == NULL)
    return ;
  TreeLinkNode *ptemp,*pconnect;
  ptemp = parentroot->next;
  pconnect = root;
  if(parentroot->right != NULL && root != parentroot->right)
        {
             pconnect->next = parentroot->right;
    pconnect = parentroot->right;
  }
  while(ptemp != NULL)
  {
    if(ptemp->left != NULL)
          {
             pconnect->next = ptemp->left;
    pconnect = ptemp->left;
    }
          if(ptemp->right != NULL)
          {
             pconnect->next = ptemp->right;
    pconnect = ptemp->right;
    }
          ptemp = ptemp->next;
  }
   

 }
 
};

Populating Next Right Pointers in Each Node II