POJ 2492 A Bug's Life （并查集）

 1 #include <iostream>
 2 #include <algorithm>
 3 #include <cstring>
 4 #include <cstdio>
 5 #include <vector>
 6 #include <cstdlib>
 7 #include <iomanip>
 8 #include <cmath>
 9 #include <ctime>
10 #include <map>
11 #include <set>
12 #include <queue>
13 using namespace std;
14 #define lowbit(x) (x&(-x))
15 #define max(x,y) (x>y?x:y)
16 #define min(x,y) (x<y?x:y)
17 #define MAX 100000000000000000
18 #define MOD 1000000007
19 #define pi acos(-1.0)
20 #define ei exp(1)
21 #define PI 3.141592653589793238462
22 #define INF 0x3f3f3f3f3f
23 #define mem(a) (memset(a,0,sizeof(a)))
24 typedef long long ll;
25 ll gcd(ll a,ll b){
26     return b?gcd(b,a%b):a;
27 }
28 const int N=2005;
29 const int mod=1e9+7;
30 int n,q;
31 int fath[2005],a[2005];
32 void init()
33 {
34     for(int i=1;i<=n;i++){
35         fath[i]=i;
36         a[i]=0;
37     }
38 }
39 int findd(int x)
40 {
41     if(x==fath[x])return x;
42     int y=findd(fath[x]);
43     a[x]=(a[x]+a[fath[x]])&1;
44     fath[x]=y;
45     return y;
46 }
47 bool SetUnion(int x,int y)
48 {
49     int fx=findd(x);
50     int fy=findd(y);
51     if(fx==fy){
52         if(a[x]==a[y]) return true;
53         else return false;
54     }
55     fath[fx]=fy;
56     if(a[y]){
57         a[fx]=a[x];
58     }
59     else{
60         a[fx]=1-a[x];
61     }
62     return false;
63 }
64 int main()
65 {
66     int t,case1=1,x,y;
67     scanf("%d",&t);
68     while(t--){
69         bool flat=true;
70         scanf("%d%d",&n,&q);
71         init();
72         for(int i=0;i<q;i++){
73             scanf("%d%d",&x,&y);
74             if(SetUnion(x,y))flat=false;
75         }
76         printf("Scenario #%d:\n",case1++);
77         if(!flat)puts("Suspicious bugs found!\n");
78         else puts("No suspicious bugs found!\n");
79     }
80     return 0;
81 }