1 //BZOJ 4602
 2 
 3 
 4 #include <stdio.h>
 5 #include <string.h>
 6 #include <iostream>
 7 #include <math.h>
 8 const int maxn = 1e+5;
 9 #define eps 1e-5
10 using namespace std;
11 
12 double ans[ maxn ];
13 int father[ maxn ];
14 int m,n;
15 int a,b,c,d;
16 bool flag;
17 int Find(int x)
18 {
19     if(father[x]!=x)
20     {
21         int t = father[x];
22         father[x]  = Find(t);
23         ans[x] *= ans[t];    //这个是权值，每一个点相对于根节点的权值
24     }
25     return father[x];
26 }
27 
28 void unio(int a,int b)
29 {
30     int root1=Find(a),root2 = Find(b);
31     if(root1!=root2)
32     {
33         father[root2] = root1;
34         ans[root2]*=ans[a]/ans[b]*(double)d/c;     //合并时，根节点的权值更新
35 
36     }else {
37         if(fabs(ans[a]/ans[b]-1.0*c/d)>eps){      
38             flag = false;
39         }
40     }
41 }
42 
43 void init()
44 {
45     for(int i = 1;i<=m;i++)
46         father[i] = i,ans[i] = 1;
47 }
48 
49 
50 int main()
51 {
52     int t;
53     while(cin>>t)
54     {
55         for(int Case = 1;Case<=t;Case++)
56         {
57             flag = true;
58             cin>>m>>n;
59             init();
60             for(int i = 1;i<=n;i++)
61             {
62                 cin>>a>>b>>c>>d;
63                 unio(a,b);
64             }
65             if(flag)
66                 cout<<"Case #"<<Case<<": Yes"<<endl;
67             else
68                 cout<<"Case #"<<Case<<": No"<<endl;
69 
70         }
71     }
72     return 0;
73 }

 1 #include <stdio.h>
 2 #include <string.h>
 3 #include <math.h>
 4 #include <iostream>
 5 const int maxn = 1e+5;
 6 using namespace std;
 7 
 8 int m,n;
 9 int father[maxn];
10 int ans[maxn];
11 
12 int Find(int x)
13 {
14     if(father[x]!=x)
15     {
16         int t = father[x];
17         ans[x] += ans[t];
18         father[x] = Find(t);
19     }
20     return father[x];
21 }
22 
23 void judge(int a,int b)
24 {
25     int root1 = Find(a);
26     int root2 =Find(b);
27     if(root1==root2)
28         printf("%d\n",ans[a]-ans[b]);
29     else printf("UNKNOWN\n");
30 }
31 
32 
33 
34 void unio(int a,int b,int c)
35 {
36     int root1 = Find(a),root2 =Find(b);
37     if(root1!=root2)
38     {
39         father[root2]=root1;
40         ans[root2] =ans[a]-ans[b]-c;
41     }
42 }
43 
44 int main()
45 {
46     int a,b,c;
47     char tmp;
48     while(scanf("%d%d",&n,&m),m||n)
49     {
50         for(int i = 1;i<=n;i++ )
51             father[i] = i,ans[i] = 0;
52         for(int i = 1;i<=m;i++)
53         {
54             cin>>tmp;
55             getchar();
56             if(tmp==‘!‘)
57             {
58                 cin>>a>>b>>c;
59                 unio(a,b,c);
60             }else {
61                 cin>>a>>b;
62                 judge(a,b);
63             }
64         }
65     }
66     return 0;
67 }