【bzoj1087】互不侵犯king 狀壓dp

狀壓dp入門題！太經典了就不多bb了。

#include<iostream>
#include<cstdio>
#include<cstring>
#define N 601
#define ll long long
using namespace std;
ll dp[85][N][85],ans;
int f[N][N],a[N],b[N],n,m,ToT;
bool judge(int x) {return !(x&(x<<1));}
bool check(int x,int y) {return !( (x&y) || (x&(y<<1)) || (x&(y>>1)) );}
int cal(int x) {
    int ret=0;
    for (;x;x>>=1)
        if (x&1) ret++;
    return ret; 
}
int main() {
    scanf("%d%d",&n,&m);
    for (int i=1;i<(1<<n);i++)
        if (judge(i)) a[++ToT]=i,b[ToT]=cal(i);
    for (int i=0;i<=ToT;i++)
        for (int j=0;j<=ToT;j++) 
            if (check(a[i],a[j])) f[i][j]=1;
    dp[0][0][0]=1;
    for (int i=1;i<=n;i++)
        for (int j=0;j<=ToT;j++)
            for (int k=0;k<=ToT;k++)
                if (f[k][j]) 
                    for  (int h=(b[k]+b[j]);h<=m;h++)
                        dp[i][j][h]+=dp[i-1][k][h-b[j]];
    for (int i=0;i<=ToT;i++) ans+=dp[n][i][m];
    printf("%lld\n",ans);   
    return 0;
}