Data Structure Linked List: Write a function to get the intersection point of two Linked Lists.

http://www.geeksforgeeks.org/write-a-function-to-get-the-intersection-point-of-two-linked-lists/

第一第二个方法比较简单，下面这段代码是第三个方法

 #include <iostream>
 #include <vector>
 #include <algorithm>
 #include <queue>
 #include <stack>
 #include <string>
 #include <fstream>
 #include <map>
 #include <set>
 using namespace std;

 struct node {
     int data;
     node *next;
     node() : data(), next(NULL) { }
     node(int d) : data(d), next(NULL) { }
 };

 void push(node* &head, int k) {
     node *new_node = new node(k);
     new_node->next = head;
     head = new_node;
 }

 void print(node* head) {
     while (head) {
         cout << head->data << " ";
         head = head->next;
     }
     cout << endl;
 }

 int getintersect(node *first, node *second) {
     int c1 = ;
     int c2 = ;
     node *p = first;
     while (p) {
         c1++;
         p = p->next;
     }
     p = second;
     while (p) {
         c2++;
         p = p->next;
     }
     if (c1 < c2) {
         swap(c1, c2);
         swap(first, second);
     }
     while (c1 != c2) {
         c1--;
         first = first->next;
     }
     while (first != second) {
         first = first->next;
         second = second->next;
     }
     return second->data;
 }

 int main() {
     node *head = new node();
     head->next = new node();
     head->next->next = new node();
     head->next->next->next = new node();
     head->next->next->next->next = new node();
     node *second = new node();
     second->next = head->next->next->next;
     cout << getintersect(head, second);
     return ;
 }

第四第五个方法不太容易想到