两个单链表是否相交

1。 判断两个链表是否有环，

如果都没有，判断最后一个节点是不是一样的。

如果一个有，一个没有，不相交。

如果都有，判断环上的一点是否在另一个单链表里。

#include <iostream>using namespace std;typedef struct stNode{int ch;struct stNode *pNext;stNode(){ch = 0; pNext = NULL;}}Node;void createList( Node &head){int i = 0;Node *p = &head;for (; i < 10; i++){p->pNext = new Node();p->pNext->ch = i;p = p->pNext;}}void printList( const Node &head){int i = 0;int times = 0;const Node *tmp = head.pNext;while (tmp){times++;cout << i++ << ": " <<  tmp->ch << endl;if ( times  == 50){break;}tmp = tmp->pNext;}}void createCrossList(Node &head){int i = 13;int crossPos = 4;Node *tmp;Node *p = &head;for ( ; i > 0; i--){p->pNext = new Node();p->pNext->ch = i;if (i == crossPos){tmp = p->pNext;}p = p->pNext;}p->pNext = tmp;}void desdoryCrossList(Node &head, Node &joinNode){Node *p = head.pNext;Node *curN = p; int i = 0;while(curN){if (curN == &joinNode){i++;if(i == 2){break;}}p = curN->pNext;cout << "delete " << curN->ch << endl;delete curN;curN = p;}}bool hasLoop(Node &head, Node *&a_meet, int &slowWork){Node *slow, *fast;slow = fast = &head;while (fast){slow = slow->pNext;slowWork++;fast = fast->pNext;if (fast){fast = fast->pNext;}else{return false;}if (slow == fast){a_meet = slow;return true;}}return false;}Node * getJoinNode(Node &head, Node &MeetNode){Node *p1 = &head;Node *p2 = &MeetNode;while (p1 != p2){p1 = p1->pNext;p2 = p2->pNext;}return p1;}int main(){Node head ;head.ch = 100;//createList(head);createCrossList(head);int len = 0;Node *p = NULL;if (hasLoop(head, p, len)){cout << "has loop" << endl;}else{cout << "do not has loop" << endl;}//printList(head);cout << "The value when meeting: " << p->ch << endl;Node *p1 = NULL;int LoopLen = 0;hasLoop(*p, p1, LoopLen);cout << "loop len:" << LoopLen << endl;p1 = getJoinNode(head, *p);cout << "Join in :" << p1->ch << endl;desdoryCrossList(head, *p1);return 0;}