描述

Background
Professor Hopper is researching the sexual behavior of a rare species of bugs. He assumes that they feature two different genders and that they only interact with bugs of the opposite gender. In his experiment, individual bugs and their interactions were easy to identify, because numbers were printed on their backs.

2
3 3
1 2
2 3
1 3
4 2
1 2
3 4

樣例輸出

Scenario #1:
Suspicious bugs found!

Scenario #2:
No suspicious bugs found!

提示

Huge input,scanf is recommended.

來源

TUD Programming Contest 2005, Darmstadt, Germany

 1 #include <iostream>
 2 #include <string>
 3 
 4 using namespace
 
 std;
 5 const int maxn = 2005;
 6 int parent[maxn];//根節點
 7 int relation[maxn];//與根節點性別關系 0同一性別 1異性
 8 
 9 int findparent(int x){
10     if(parent[x]!=x){
11         int root=findparent(parent[x]);
12         relation[x]=(relation[x]+relation[parent[x]])%2;
13         parent[x]=root;
14     }
15     return parent[x];
16 }
17 
18 bool merge(int x,int y){
19     int px=findparent(x),py=findparent(y);
20     if(px==py){
21         if(relation[x]==relation[y])return false;
22         return true;
23     }
24     relation[py]=(relation[x]-relation[y]+1)%2;
25     parent[py]=px;
26     return true;
27 }
28 
29 int main()
30 {
31     int scene;
32     scanf("%d",&scene);
33     for(int i=1;i<=scene;i++)
34     {
35         bool flag=true;
36         int n, k;
37         scanf("%d%d",&n,&k);
38         for(int i=1;i<=n;i++)
39         {
40             relation[i]=0;
41             parent[i]=i;
42         }
43         while(k--){
44             int x,y;
45             scanf("%d%d",&x,&y);
46             if(flag==true)
47             {
48                 flag=merge(x,y);
49                 if(!flag){
50                     printf("Scenario #%d:\nSuspicious bugs found!\n\n",i);
51                 }
52             }
53         }
54         if(flag)
55             printf("Scenario #%d:\nNo suspicious bugs found!\n\n",i);
56     }
57     return 0;
58 }

只是把食物鏈刪改了一下，比前者要簡單

18.9.17 poj2492 A Bug's Life