方格取数--状压DP or 网络流

题意：http://acm.hdu.edu.cn/showproblem.php?pid=1565

取不相邻的点是权值最大。

这题可以网络流做，暂时先DP一下，网络流明天学一下~~

 #define IOS ios_base::sync_with_stdio(0); cin.tie(0);
 #include <cstdio>//sprintf islower isupper
 #include <cstdlib>//malloc  exit strcat itoa system("cls")
 #include <iostream>//pair
 #include <fstream>//freopen("C:\\Users\\13606\\Desktop\\草稿.txt","r",stdin);
 #include <bitset>
 //#include <map>
 //#include<unordered_map>
 #include <vector>
 #include <stack>
 #include <set>
 #include <string.h>//strstr substr
 #include <string>
 #include <time.h>// srand(((unsigned)time(NULL))); Seed n=rand()%10 - 0~9;
 #include <cmath>
 #include <deque>
 #include <queue>//priority_queue<int, vector<int>, greater<int> > q;//less
 #include <vector>//emplace_back
 //#include <math.h>
 //#include <windows.h>//reverse(a,a+len);// ~ ! ~ ! floor
 #include <algorithm>//sort + unique : sz=unique(b+1,b+n+1)-(b+1);+nth_element(first, nth, last, compare)
 using namespace std;//next_permutation(a+1,a+1+n);//prev_permutation
 //******************
 int abss(int a);
 int lowbit(int n);
 int Del_bit_1(int n);
 int maxx(int a,int b);
 int minn(int a,int b);
 double fabss(double a);
 void swapp(int &a,int &b);
 clock_t __STRAT,__END;
 double __TOTALTIME;
 void _MS(){__STRAT=clock();}
 void _ME(){__END=clock();__TOTALTIME=(double)(__END-__STRAT)/CLOCKS_PER_SEC;cout<<"Time: "<<__TOTALTIME<<" s"<<endl;}
 //***********************
 #define rint register int
 #define fo(a,b,c) for(rint a=b;a<=c;++a)
 #define fr(a,b,c) for(rint a=b;a>=c;--a)
 #define mem(a,b) memset(a,b,sizeof(a))
 #define pr printf
 #define sc scanf
 #define ls rt<<1
 #define rs rt<<1|1
 typedef long long ll;
 const double E=2.718281828;
 const double PI=acos(-1.0);
 //const ll INF=(1LL<<60);
 const int inf=(<<);
 const double ESP=1e-;
 const int mod=(int)1e9+;
 const int N=(int)1e6+;

 int ok_num[N];
 int dp[][];
 int a[][];

 bool OK(int n,int x)
 {
     int F[];
     F[]=;
     for(int i=;i<=n;++i)
         F[i]=(x>>(n-i))&;
     for(int i=;i<n;++i)
         if(F[i]&&F[i+])return ;
     return ;
 }
 int get(int now,int state,int n)
 {
     int F[];
     F[]=;
     for(int i=;i<=n;++i)
         F[i]=(state>>(n-i))&;

     int temp=;
     for(int i=;i<=n;++i)
         if(F[i])temp+=a[now][i];
     return temp;
 }

 void solve(int n)
 {
     int cnt=;
     int tot=(<<n)-;
     for(int i=;i<=tot;++i)
     {
         if(OK(n,i))
             ok_num[++cnt]=i;
     }
 //    cout<<cnt<<endl;
     for(int i=;i<=n;++i)
         for(int j=;j<=n;++j)
             sc("%d",&a[i][j]);
     for(int i=;i<=cnt;++i)
         dp[][i]=dp[][i]=;
     for(int i=;i<=n;++i)
     {
         for(int j=;j<=cnt;++j)
         {
             int temp=get(i,ok_num[j],n);
         //    dp[1][j]=temp;
             for(int k=;k<=cnt;++k)
             {
                 if((ok_num[j]&ok_num[k])==)
                     dp[][j]=maxx(dp[][j],temp+dp[][k]);
             }
         }
         for(int j=;j<=cnt;++j)
             dp[][j]=dp[][j],dp[][j]=;
     }
     int ans=;
     for(int i=;i<=cnt;++i)
         ans=maxx(ans,dp[][i]);
     pr("%d\n",ans);
 }

 int main()
 {
     int n;
     while(~sc("%d",&n))solve(n);
     return ;
 }

 /**************************************************************************************/

 int maxx(int a,int b)
 {
     return a>b?a:b;
 }

 void swapp(int &a,int &b)
 {
     a^=b^=a^=b;
 }

 int lowbit(int n)
 {
     return n&(-n);
 }

 int Del_bit_1(int n)
 {
     return n&(n-);
 }

 int abss(int a)
 {
     return a>?a:-a;
 }

 double fabss(double a)
 {
     return a>?a:-a;
 }

 int minn(int a,int b)
 {
     return a<b?a:b;
 }