POJ 2531 Network saboteur (DFS)

Source: Internet
Author: User

Network saboteur
Time Limit: 2000MS Memory Limit: 65536K
Total Submissions: 9364 Accepted: 4417

Description

A University Network is composed of N computers. System administrators gathered information on the traffic between nodes, and carefully divided the network into and the subnet Works in order to minimize traffic between parts.
A disgruntled computer science student Vasya, after being expelled from the university, decided to has his revenge. He hacked into the university network and decided to reassign computers to maximize the traffic between.
Unfortunately, he found, calculating such worst subdivision is one of the those problems he, being a student, failed to so Lve. So he asks-a more successful CS student, to-help him.
The traffic data is given in the form of Matrix C, where Cij is the amount of data sent between and ith jth (nodes = Cji, Cii = 0). The goal is to divide the network nodes into the and the disjointed subsets A and B so as to maximize the SUM∑CIJ (I∈A,J∈B).

Input

The first line of input contains a number of nodes N (2 <= n <= 20). The following n lines, containing n space-separated integers each, represent the traffic matrix C (0 <= Cij <= 10000 ).
Output file must contain a single integer-the maximum traffic between the subnetworks.

Output

Output must contain a single integer-the maximum traffic between the subnetworks.

Sample Input

30 50 3050 0 4030 40 0

Sample Output

90

Baidu took a moment to know the idea, continue to work hard.

。。

Test instructions: Divides a connected set into two disconnected sets. The maximum amount of information exchanged between the two sets.

Each point (computer) can be made up of two choices. To a set or B set.

Classify one point at a time. Find it immediately and have a collection of exchange information.


#include <stdio.h> #include <queue> #include <map> #include <string> #include <string.h> using namespace std; #define N 25const int inf=0x1f1f1f1f;int g[n][n];int ans,n;bool f[n];void dfs (int u,int sum) {    if (U >=n)    {        Ans=max (ans,sum);        return;    }    int i,tmp=0;    F[u]=false;         Divide the point u into set a    for (i=0;i<u;i++)   //Seek point U and set B to exchange the amount of information        if (f[i]==true)            tmp+=g[u][i];    DFS (U+1,SUM+TMP);    F[u]=true;          Divide the point u into set B for    (i=tmp=0;i<u;i++)//Seek points U and set a exchange amount of information        if (f[i]==false)        tmp+=g[u][i];    DFS (U+1,SUM+TMP);} int main () {    int i,j;    while (scanf ("%d", &n)!=-1)    {        for (i=0; i<n; i++)            for (j=0; j<n; j + +)                scanf ("%d", &g[ I][J]);        ans=0;        DFS (0,0);        printf ("%d\n", ans);    }    return 0;}


POJ 2531 Network saboteur (DFS)

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.