打印路径（单链表实现）

 1 #include <bits/stdc++.h>
 2 #define _for(i,a,b) for(int i = (a);i < (b);i ++)
 3 #define pb push_back
 4 
 5 using namespace std;
 6 
 7 struct Node
 8 {
 9     int data;
10     int from,to;
11     Node *next;
12 };
13 
14 ostream& operator << (ostream& os,Node* p)
15 {
16     if(p == NULL) return os;
17     os << p->next << p->from << " " << p->to << " " << p->data << endl;
18     return os;
19 }
20 
21 void add(Node* &p,int u ,int v,int da)
22 {
23     while(p && p->next!=NULL)
24         p = p->next;
25     Node *q = new(Node);
26     q->next = NULL,q -> from = u,q -> to = v,q -> data = da;
27     if(p)    p -> next = q;
28     else    p = q;
29 }
30 
31 int main()
32 {
33     Node *path = NULL;
34     add(path,1,2,39);
35     add(path,2,3,39);
36     cout << path;
37     return 0;
38 }