poj1703

题目大意：一共有两个类，两种操作D X Y表示X Y在不同的类里面，A X Y 询问X Y之间的关系(未知，相同，不同)

分析：简单带权并查集，D[i]表示与i对立的类，维护好这个变量就可以了。

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <set>
 5 #include <algorithm>
 6 #include <map>
 7 #include <queue>
 8 #include<vector>
 9 #define maxn 100010
10 #define maxm 100010
11 #define mod 1000000000000000000
12 #define INF 0x3fffffff
13 using namespace std;
14 int father[maxn];
15 int n;
16 int d[maxn];
17 void init(){
18     for(int i=0;i<=n;++i){
19         father[i]=i;
20         d[i]=-1;
21     }
22 }
23 int Find(int x){
24     return father[x]==x?x:father[x]=Find(father[x]);
25 }
26 void Union(int x,int y){
27     x =Find(x);
28     y =Find(y);
29     if(x!=y)father[x]=y;
30 }
31 int main ()
32 {
33     int t,m;
34     scanf("%d",&t);
35     while(t--){
36         scanf("%d%d",&n,&m);
37         init();
38         char ch[10];
39         int x,y;
40         for(int i=0;i<m;++i){
41             scanf("%s%d%d",ch,&x,&y);
42             int fx = Find(x);
43             int fy = Find(y);
44             if(ch[0]=='A'){
45                 if(fx==fy)printf("In the same gang.\n");
46                 else if(fx == Find(d[y]))printf("In different gangs.\n");
47                 else printf("Not sure yet.\n");
48             }
49             else {
50                 if(d[x]==-1){
51                     d[x]=fy;
52                 }
53                 if(d[y]==-1){
54                     d[y]=fx;
55                 }
56                 Union(x,d[fy]);
57                 Union(y,d[fx]);
58             }
59         }
60     }
61 }