HDU 5765 Bonds（状压DP）

#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;
int n,m,T,Cas=1,x[400],y[400],mp[(1<<20)+5],ans,sta[21];
bool g[21][21],dp[(1<<21)+5];
int main(){
    scanf("%d",&T);
    memset(mp,-1,sizeof(mp));
    for(int i=0;i<20;i++)mp[1<<i]=i;
    while(T--){
        scanf("%d%d",&n,&m);
        memset(g,0,sizeof(g));
        memset(sta,0,sizeof(sta));
        for(int i=1;i<=m;i++){
            scanf("%d%d",&x[i],&y[i]);
            if(x[i]<y[i])swap(x[i],y[i]);
            g[x[i]][y[i]]=g[y[i]][x[i]]=1;
            sta[x[i]]|=1<<y[i];
            sta[y[i]]|=1<<x[i];
        }dp[0]=1;
        for(int s=1;s<(1<<n);s++){
            dp[s]=0;
            if(s==(s&-s)){dp[s]=1;continue;}
            for(int x=0;x<n;x++){
                if(s&(1<<x)){if(dp[s^(1<<x)]&&(sta[x]&s)){dp[s]=1;break;}}
            }
        }printf("Case #%d:",Cas++);
        for(int i=1;i<=m;i++){
            ans=0;
            for(int s1=0;s1<(1<<(n-x[i]-1));s1++)
            for(int s2=0;s2<(1<<(x[i]-y[i]-1));s2++)
            for(int s3=0;s3<(1<<y[i]);s3++){
                int s=s3|(s2<<(y[i]+1))|(1<<x[i])|(s1<<(x[i]+1));
                if(dp[s]&&dp[((1<<n)-1)^s])ans++;
            }printf(" %d",ans);
        }puts("");
    }return 0;
}