Hackers ' crackdown-uva11825 pressure DP

Problem H

Hackers ' crackdown
Input: standard input

Output: Standard Output

Miracle corporations have a number of system services running in a distributed computer system which are a prime target for Hackers. The system is basically a set of n computer nodes with each of the them running a set of N services. Note that, the set of services running on every node is same everywhere in the network. A hacker can destroy a service by running a specialized exploit for this service in all the nodes.

One day, a smart hacker collects necessary exploits for all these N services and launches an attack on the system . He finds a security hole that gives him just enough time to run a single exploit in each computer. These exploits has the characteristic, its successfully infects the computer where it is originally run and all the Neighbor computers of that node.

Given A network description, find the maximum number of services that the hacker can damage.

Input

There'll is multiple test cases in the input file. A test case is begins with an integer N (1<=n<=16)and the number of nodes in the network. The nodes is denoted by 0 to N-1. Each of the following N lines describes the neighbors of a node. Line I (0<=i<n)represents the description of node I. The description for node I starts with a integer m (number of neighbors for node i), followed bym integers in the range of 0 to N-1, each denoting a neighboring node of node I.

The end of input would be denoted by a case with N = 0. This case is should not being processed.

Output

For each test case, print a line in the format, ' casex:y', where X is the case number & Y is the maximum possible number of services can damaged.

Sample Input	Output for Sample Input
3 2 1 2 2 0 2 2 0 1 4 1 1 1 0 1 3 1 2 0	Case 1:3 Case 2:2

Test instructions: There are n computers that perform 1-n projects together, and for each computer you have a chance to make it impossible to work on a project while the computer with which it is directly connected has received the impact. If a project is not implemented by a computer, the project will be paralyzed, and the maximum number of projects can be paralysed.

Idea: The first day of the computer and its direct connection to the first form of pressure, indicating which paralysis. S represents the maximum number of damaged works that have been paralyzed by the current computer, so Dp[s]=max (dp[s],dp[s2]+1) If S-S2 can paralyze a project. Here is also a subset of the implementation techniques see Code.

The AC code is as follows:

[CPP]View Plaincopy

2. #include <cstdio>
4. #include <cstring>
6. #include <algorithm>
8. Using namespace std;
10. int n,m,pow2[20],val[20],c[100010],dp[100010];
12. int main ()
14. {
16. int t=0,i,j,k,total;
18. Pow2[0]=1;
20. For (i=1;i<=16;i++)
22. pow2[i]=pow2[i-1]*2;
24. while (~scanf ("%d", &n) && n>0)
26. {
28. For (i=0;i<n;i++)
30. {
32. Val[i]=pow2[i];
34. scanf ("%d", &m);
36. For (j=1;j<=m;j++)
38. {
40. scanf ("%d", &k);
42. VAL[I]+=POW2[K];
44. }
46. }
48. Total=pow2[n]-1;
50. For (i=1;i<=total;i++)
52. {
54. c[i]=0;
56. For (j=0;j<n;j++)
58. if (I&pow2[j])
60. C[I]|=VAL[J];
62. }
64. For (i=1;i<=total;i++)
66. {
68. dp[i]=0;
70. For (k=i;k>0;k= (k-1) &i)
72. if (c[k]==total)
74. Dp[i]=max (dp[i],dp[i^k]+1);
76. }
78. printf ("Case%d:%d\n", ++t,dp[total]);
80. }
84. }

Hackers ' crackdown-uva11825 pressure DP