POJ 2531 decentralization Problem DFS algorithm

Test instructions: A set (matrix) m[i][j]=m[j][i] weight, divided into two sets, so that its weight value is maximum. Note: Weights in the same set can only be counted one.

Idea: DFS

1. Assume that all are in the collection 0
2. Get the collection 1 when you traverse the ID.
3. If the overall weight of the set 0 associated with the ID is to be added, the overall weight value should be reduced
4. If you get a set of 1 weights, go back to DFS, and then a backtracking operation

Questions to note on the code:

 for (int1; i < n; i++)    {        if (tmp > data)        {            DFS (i, TMP);             0 ;        }    }

Here is a backtracking operation, if you do not execute DFS, I put to set 1 is not appropriate, so put in the collection 0

Code to solve the problem:

#include <iostream>#include<cstdio>#include<string.h>using namespacestd;intmap[ -][ -];intdep[ -];intN, ans;voidDfsintIdintdata) {Dep[id]=1; intTMP =data;  for(inti =0; I < n; i++)    {        if(Dep[i] = =0) tmp + =Map[i][id]; ElseTMP-=Map[i][id]; }    if(ANS < tmp) ans =tmp;  for(inti = ID +1; I < n; i++)    {        if(tmp >data)            {DFS (I, TMP); Dep[i]=0; }    }}intMain () {scanf ("%d", &N);  for(inti =0; I < n; i++)         for(intj =0; J < N; J + +) scanf ("%d", &Map[i][j]); memset (DEP,0,sizeof(DEP)); Ans=0; DFS (0,0); printf ("%d\n", ans); return 0;}

POJ 2531 decentralization Problem DFS algorithm