hdu_1213

　　在算法上松懈了好久，决心开始慢慢捡起来了。一开始先跟初学一样吧。基础一点，也能发现以前自己的问题。

 1 #include<iostream>

 2 #include<cstdio>

 3 #define MAXN 1111

 4 int TestCase = 0;

 5 int N,M;

 6 int tr[MAXN];

 7 int tr_find(int x)

 8 {

 9     while(tr[x] != x)

10         x = tr[x];

11     return x;

12 }

13 void tr_merge(int a,int b)

14 {

15     int ra = tr_find(a);

16     int rb = tr_find(b);

17     if(ra!=rb)

18         tr[ra] = rb;

19     return;

20 }

21 int main()

22 {

23 //    freopen("in.txt","r",stdin);

24     scanf("%d",&TestCase);

25     while(TestCase --) {

26         scanf("%d%d",&N,&M);

27         for(int i = 1; i <= N; i++)

28             tr[i] = i;

29         while(M--) {

30             int a,b;

31             scanf("%d%d",&a,&b);

32             tr_merge(a,b);

33         }

34         int s = 0;

35         for(int i = 1; i <= N; i++)

36 //            std::cout<<" "<<tr[i];

37             if(tr[i] == i)

38                 ++s;

39         printf("%d\n",s);

40     }

41 }