1671. Anansi's Cobweb（并查集）

1671

并查集 对于询问删除边之后的连通块 可以倒着加边 最后再倒序输出

 1 #include <iostream>

 2 #include<cstdio>

 3 #include<cstring>

 4 #include<algorithm>

 5 #include<stdlib.h>

 6 using namespace std;

 7 #define N 100010

 8 int p[N],father[N],a,b,f[N];

 9 int pp[N];

10 struct node

11 {

12     int x,y;

13 }ed[N];

14 int find(int x)

15 {

16     if(father[x]!=x)

17     father[x] = find(father[x]);

18     return father[x];

19 }

20 void add(int a,int b)

21 {

22     int x = find(a);

23     int y = find(b);

24     if(x!=y)

25     father[x] = y;

26 }

27 int main()

28 {

29     int i,n,m,q;

30     while(scanf("%d%d",&n,&m)!=EOF)

31     {

32         memset(f,0,sizeof(f));

33         for(i =1; i <= n ; i++)

34         father[i] = i;

35         for(i = 1; i <= m ; i++)

36         {

37             scanf("%d%d",&ed[i].x,&ed[i].y);

38         }

39         scanf("%d",&q);

40         for(i = 1; i <= q ;i++)

41         {

42             scanf("%d",&p[i]);

43             f[p[i]] = 1;

44         }

45         for(i = 1; i <= m ; i++)

46         {

47             if(!f[i])

48             add(ed[i].x,ed[i].y);

49         }

50         int num = 0;

51         for(i = 1; i <= n ; i++)

52         if(father[i]==i)

53         num++;

54         pp[1] = num;

55         int o = 1;

56         for(i = q ; i>1 ; i--)

57         {

58             int x = find(ed[p[i]].x);

59             int y = find(ed[p[i]].y);

60             if(x==y)

61             {

62                 pp[++o] = num;

63                 continue;

64             }

65             else

66             {

67                 father[x] = y;

68                 num--;

69                 pp[++o] = num;

70             }

71         }

72         for(i = o ; i > 1 ; i--)

73         printf("%d ",pp[i]);

74         printf("%d\n",pp[1]);

75     }

76     return 0;

77 }

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