Leetcode oj:intersection of two Linked Lists (insertion of two linked lists)

Write a program to find the node at which the intersection of the singly linked lists begins.

For example, the following, linked lists:

A:          a1→a2                                        c1→c2→c3                               B:     b1→b2→b3

Begin to intersect at node C1.

Find out the position of the first merged node (or insert), note that the complexity is O (N), then go through two linked lists, to find out the length of the long list of the "cut", the following is a good comparison, the code is as follows:

1 classSolution {2  Public:3ListNode *getintersectionnode (ListNode *heada, ListNode *headb) {4         intlen1, Len2;5Len1 = Len2 =0;6ListNode * p =Heada;7ListNode * q =headb;8          while(p) {9p = p->Next;Tenlen1++; One         } A          while(q) { -Q = q->Next; -len2++; the         } -         if(Len1 >len2) { -             intdiff = len1-Len2; -              while(diff--) +Heada = heada->Next; -}Else if(Len2 >len1) { +             intdiff = len2-len1; A              while(diff--) atHEADB = headb->Next; -         } -          while(Heada) { -             if(Heada = =headb) -                 returnHeada; -Heada = heada->Next; inHEADB = headb->Next; -         } to         returnNULL; +     } -};

Leetcode oj:intersection of two Linked Lists (insertion of two linked lists)