bzoj 1087: [SCOI2005]互不侵犯King

#include<cstdio>
#include<iostream>
using namespace std;
const int maxn = 11;
inline int read() {
    int x=0;
    char c=getchar() ;
    while(c<‘0‘||c>‘9‘);
    while(c<=‘9‘&&c>=‘0‘) {
        x=x*10+c-‘0‘;c=getchar();
    }
    return x;
}
int k,n;
long long dp[maxn][83][1<<maxn];
int num[1<<maxn];
int main() {
    n=read();k=read();
    dp[0][0][0]=1;
    for(int kk,i=1;i<1<<n;++i) {
        kk=i;
        while(kk) {
            if(kk&1)num[i]++;kk>>=1;
        }
    }
    for(int i=1;i<=n;++i) {
        for(int j=0;j<=k;++j) {
            for(int k=0;k<(1<<n);++k) {
                if(k&(k>>1)||k&(k<<1))continue;
                if(num[k]>j)continue;
                for(int p=0;p<(1<<n);++p) {
                    if(p&(p<<1)||p&(p>>1)||(p<<1)&k||(p>>1)&k||p&k)continue;                    
                    dp[i][j][k]+=dp[i-1][j-num[k]][p];
                }
            }
        }
    }
    long long ans=0;
    for(int i=0;i<(1<<n);++i) {
        ans+=dp[n][k][i];
    }
    printf("%lld\n",ans);
    return 0;
}