给定两个单链表，编写算法查找两个链表的公共结点

两个有公共结点而部分重叠的单链表，拓扑形状看起来像Y  而非X

LinkList Search_1st_Common(LinkList L1 , LinkList L2){
  int len1 = length(L1),  len2 = length(2);
  LinkLsit longlist, shortlist;
  int dist;
  if(len1 > len2){
    longlist = L1>next;  shortlist = L2->next;
    dist = len1 - len2;
  else{
    longlist = L2>next;  shortlist = L1->next;
    dist = len2 - len1;
 
  while(dist--)
    longlist = longlist->next;
  
  while(longlist !=NULL){
    if(longlist == shortlist)
        return longlist;
    else{
        longlist = longlist->next;
        shortlist = shortlist->next;
    }
  }
return NULL;
}
        





}