poj2531 (Network saboteur)

Title Address: Network saboteur

Main topic:

A school's network consists of n computers, in order to reduce traffic between network nodes, the school will divide n nodes into two sets (A, B), student Vasya intends to invade the school network, resulting in the largest flow between the collection, The flow meter between the collections is the sum of the traffic from all nodes in the A collection to all nodes in the B collection.

For example, 1, 2, 3

Decomposition set, a can be {1} at this time B is {2, 3}. Then calculate 1-2 of the traffic plus 1-3 of the traffic for sum to find out all the possible sum to take the largest one.

Problem Solving Ideas:

Test instructions may be a bit difficult to understand. Data is very water and directly enumerates violence. (It should be timed out as usual)

Code:

1#include <algorithm>2#include <iostream>3#include <sstream>4#include <cstdlib>5#include <cstring>6#include <cstdio>7#include <string>8#include <bitset>9#include <vector>Ten#include <queue> One#include <stack> A#include <cmath> -#include <list> - //#include <map> the#include <Set> - using namespacestd; - /***************************************/ - #definell Long Long + #defineInt64 __int64 - #definePI 3.1415927 + /***************************************/ A Const intINF =0x7f7f7f7f; at Const DoubleEPS = 1e-8; - Const DoublePie=acos (-1.0); - Const intd1x[]= {0,-1,0,1}; - Const intd1y[]= {-1,0,1,0}; - Const intd2x[]= {0,-1,0,1}; - Const intd2y[]= {1,0,-1,0}; in Const intfx[]= {-1,-1,-1,0,0,1,1,1}; - Const intfy[]= {-1,0,1,-1,1,-1,0,1}; to Const intdirx[]= {-1,1,-2,2,-2,2,-1,1}; + Const intdiry[]= {-2,-2,-1,-1,1,1,2,2}; - /*Vector <int>map[n];map[a].push_back (b); int len=map[v].size ();*/ the /***************************************/ * voidOpenFile () $ {Panax NotoginsengFreopen ("data.in","RB", stdin); -Freopen ("Data.out","WB", stdout); the } +priority_queue<int>Qi1; Apriority_queue<int, vector<int, greater<int> >Qi2; the /********************** Gorgeous split line, above for template part *****************/ + intmap[ -][ -]; - intvis[ -]; $ intMaxx; $ intN; - intDFS (intXintsum) - { the     inti,j; -      for(i=1; i<=n; i++)Wuyi     { the         if(Vis[i]) -              for(j=1; j<=n; J + +) Wu             { -                 if(!Vis[j]) Aboutsum+=Map[i][j]; $             } -     } -     if(sum>Maxx) -maxx=sum; A      for(i=x; i<=n; i++) +     { thevis[i]=1; -DFS (i+1,0); $vis[i]=0; the     } the } the intMain () the { -      while(SCANF ("%d", &n)! =EOF) in     { thememset (Map,0,sizeof(map)); thememset (Vis,0,sizeof(Vis)); About         inti,j; the          for(i=1; i<=n; i++) the              for(j=1; j<=n; J + +) thescanf"%d",&map[i][j]); +vis[1]=1; -maxx=-1; theDFS (2,0);Bayiprintf"%d\n", Maxx); the     } the     return 0; -}

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