A Bug‘s Life
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.
Problem
Given a list of bug interactions, decide whether the
experiment supports his assumption of two genders with no homosexual
bugs or if it contains some bug interactions that falsify it.
Input
The first line of the input contains the number of scenarios.
Each scenario starts with one line giving the number of bugs (at least
one, and up to 2000) and the number of interactions (up to 1000000)
separated by a single space. In the following lines, each interaction is
given in the form of two distinct bug numbers separated by a single
space. Bugs are numbered consecutively starting from one.
Output
The output for every scenario is a line containing "Scenario
#i:", where i is the number of the scenario starting at 1, followed by
one line saying either "No suspicious bugs found!" if the experiment is
consistent with his assumption about the bugs‘ sexual behavior, or
"Suspicious bugs found!" if Professor Hopper‘s assumption is definitely
wrong.
Sample Input
2 3 3 1 2 2 3 1 3 4 2 1 2 3 4
Sample Output
Scenario #1: Suspicious bugs found! Scenario #2: No suspicious bugs found!
1 #include<iostream>
2 #include<cstdio>
3 #include<cmath>
4 #include<cstring>
5 #include<algorithm>
6 #include<queue>
7 #include<map>
8 #include<set>
9 #include<vector>
10 #include<cstdlib>
11 #include<string>
12 #define eps 0.000000001
13 typedef long long ll;
14 typedef unsigned long long LL;
15 using namespace std;
16 const int N=2000+100;
17 int flag[N];
18 int parent[N];
19 int m,n;
20 void init(){
21 for(int i=0;i<=n;i++)parent[i]=i;
22 memset(flag,0,sizeof(flag));
23 }
24 int find(int x){
25 if(parent[x]!=x){
26 int root=parent[x];
27 parent[x]=find(parent[x]);
28 flag[x]=(flag[x]+flag[root])%2;
29 }
30 return parent[x];
31 }
32 /*
33 int find(int x){
34 int r=x;
35 while(r!=parent[r])r=parent[r];
36 int i=x;
37 int j;
38 while(i!=r){
39 flag[i]=(flag[i]+flag[parent[i]])%2;
40 j=parent[i];
41 parent[i]=r;
42 i=j;
43 }
44 return r;
45 }*/
46 void Union(int x,int y){
47 int xx=find(x);
48 int yy=find(y);
49 parent[xx]=yy;
50 flag[xx]=(flag[y]+flag[x]+1)%2;
51 }
52 int main()
53 {
54 //freopen("text.txt","r",stdin);
55 int T,kase;
56 scanf("%d",&T);
57 for(int kase=1;kase<=T;kase++)
58 {
59 scanf("%d%d",&n,&m);
60 init();
61 int flag1=0;
62 for(int i=0;i<m;i++)
63 {
64 int x,y;
65 scanf("%d%d",&x,&y);
66 if(flag1)
67 continue;
68 int fx=find(x);
69 int fy=find(y);
70 if(fx==fy)
71 {
72 if(flag[x]==flag[y])
73 flag1=1;
74 }
75 else
76 Union(x,y);
77 }
78 printf("Scenario #%d:\n",kase);
79 if(flag1)
80 printf("Suspicious bugs found!\n");
81 else
82 printf("No suspicious bugs found!\n");
83 if(kase!=T)
84 printf("\n");
85 }
86 return 0;
87 }