A Bug's Life POJ - 2492

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <algorithm>
 4 #include <queue>
 5 #include <vector>
 6 #include <cmath>
 7 
 8 using namespace std;
 9 
10 #define ll long long
11 #define pb push_back
12 #define fi first
13 #define se second
14 
15 const int N = 2000 << 1;
16 struct node
17 {
18     int rt, v;
19 }fa[N];
20 
21 int Find(int x)
22 {
23     if(fa[x].rt == x) return x;
24     else{
25         int tmp = fa[x].rt;
26         fa[x].rt = Find(tmp);
27         fa[x].v = (fa[x].v + fa[tmp].v) % 2;
28         return fa[x].rt;
29     }
30 }
31 
32 bool Union(int x, int y)
33 {
34     int fax = Find(x);
35     int fay = Find(y);
36     if(fax != fay){
37         fa[fay].rt = fax;
38         fa[fay].v = (fa[x].v + 1 - fa[y].v) % 2;
39         return true;
40     }else{
41         if(0 == (fa[x].v + 1 - fa[y].v) % 2) return true;
42         else return false;
43     }
44 }
45 
46 void solve()
47 {   
48     int T;
49     scanf("%d", &T);
50     for(int _case = 1; _case <= T; ++_case){
51         int n, m;
52         scanf("%d%d", &n, &m);
53         for(int i = 0; i <= n; ++i){
54             fa[i].rt = i;
55             fa[i].v = 0;
56         }
57         vector<pair<int ,int > > info;
58         int x, y;
59         for(int i = 1; i <= m; ++i){
60             scanf("%d%d", &x, &y);
61             info.pb({x, y});
62         }
63 
64         int error = 0;
65         for(int i = 0; i < m; ++i){
66             x = info[i].fi;
67             y = info[i].se;
68             if(!Union(x, y)){
69                 error = 1;
70                 break;
71             }
72         }
73 
74         printf("Scenario #%d:\n", _case);
75         printf("%s\n\n", error == 1 ? "Suspicious bugs found!" : "No suspicious bugs found!");
76     }
77 }
78 
79 int main()
80 {
81 
82     solve();
83 
84     return 0;
85 }