方格取数(1)（HDU 1565状压dp）

#include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <vector>
#include <string>
#include <cctype>
#include <complex>
#include <cassert>
#include <utility>
#include <cstring>
#include <cstdlib>
#include <iostream>
#include <algorithm>
using namespace std;
typedef pair<int,int> PII;
typedef long long ll;
#define lson l,m,rt<<1
#define pi acos(-1.0)
#define rson m+1,r,rt<<11
#define All 1,N,1
#define read freopen("in.txt", "r", stdin)
const ll  INFll = 0x3f3f3f3f3f3f3f3fLL;
const int INF= 0x7ffffff;
const int mod =  1000000007;
int n,now[20001],total[20001],a[20][20];
int nnum,par[20001],dp[20001],dp1[20001];
void state(int i,int k,int s,int sum){
        if(k>=n){
            now[++nnum]=s;
            total[nnum]=sum;
            return;
        }
        state(i,k+2,s|(1<<k),sum+a[i][k]);
        state(i,k+1,s,sum);
}
void solve(){
    for(int i=0;i<n;++i){
            nnum=0;
        state(i,0,0,0);
        memset(dp,0,sizeof(dp));
        for(int j=1;j<=nnum;++j)
        for(int l=1;l<=nnum;++l)
        if((now[j]&now[l])==0){
        dp[j]=max(dp[j],dp1[l]+total[j]);
        }
        for(int l=1;l<=nnum;++l){
            dp1[l]=dp[l];
        }
    }
    int maxv=-1;
    for(int i=1;i<=nnum;++i){
        maxv=max(maxv,dp1[i]);
    }
    printf("%d\n",maxv);
}
int main()
{
    while(~scanf("%d",&n)){
        for(int i=0;i<n;++i)
        for(int j=0;j<n;++j)
        scanf("%d",&a[i][j]);
        memset(dp1,0,sizeof(dp1));
        solve();
    }
return 0;
}