LeetCode Populating Next Right Pointers in Each Node II

 // 173ms
 1 /**
 * 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) {}
 * };
 */
class Solution {
public:
    int flag;
    TreeLinkNode *findHead(TreeLinkNode ** q)
    {
        TreeLinkNode *p;
        p=*q;
             
        while(p)
        {
            if(p->left)
            {
                flag=0;
                *q=p;
                return p->left; 
            }
                
            if(p->right)
            {
                flag=1;
                *q=p;
                return p->right;
            }
                
            p=p->next;
        }
        *q=p;
        return NULL;
    }
    TreeLinkNode *findNext(TreeLinkNode ** q)
    {
        TreeLinkNode *p;
        p=*q;
        if(*q==NULL)
            return NULL;
        if(flag==0&&p->right)  
        {
            flag=1;
            *q=p;
            return p->right;
        }
        if(flag||(flag==0&&p->right==NULL))
        {
            p=p->next;
        }
        while(p)
        {
            if(p->left)
            {
                flag=0;
                *q=p;
                return p->left; 
            }
                
            if(p->right)
            {
                flag=1;
                *q=p;
                return p->right;
            }
              
            p=p->next;
        }
        *q=p; 
        return NULL;
    }
    void connect(TreeLinkNode *root) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        TreeLinkNode *p,*q,*t,*tt;
        if(root==NULL)
            return;
        t=root;
        
        while(t)
        {    
            p=findHead(&t);
            tt=p;
            while(q=findNext(&t))
            {
                p->next=q;
                p=q;
            }
            t=tt;
        }       
    }
};