UVA11795 Mega Man's Mission

Posted 2020-10-14 white_hat_hacker

状压dp

#include<cstdio>
#include<cstdlib>
#include<algorithm>
#include<cstring>
#include<vector>
#include<queue>
#define MAXN 20
#define ll long long
using namespace std;
int n;
vector<int> G[MAXN];
ll f[1<<MAXN];
int vis[1<<MAXN];
void solve(){
    for(int i=0;i<MAXN;i++) G[i].clear();
    memset(f,0,sizeof(f));
    memset(vis,0,sizeof(vis));
    scanf("%d",&n);
    for(int i=0;i<=n;i++){
        char ch[10]={0};
        scanf("%s",ch+1);
        for(int j=1;j<=n;j++){
            if(ch[j]-48){
                G[i].push_back(j);
            }
        }
    }
    queue<int> q;
    f[(1<<n)-1]=1;
    vis[(1<<n)-1]=1;
    q.push((1<<n)-1);
    while(!q.empty()){
        int S=q.front();q.pop();
        int b[MAXN]={0};
        for(int i=0;i<G[0].size();i++){
            b[G[0][i]]=1;
        }
        int t=S,cnt=1;
        for(int i=0;i<n;i++){
            if(~(S>>i)&1){
                for(int j=0;j<G[i+1].size();j++){
                    b[G[i+1][j]]=1;
                }
            }
        }
        for(int i=0;i<n;i++){
            if(((S>>i)&1)&&b[i+1]){
                int dS=S^(1<<i);
                f[dS]+=f[S];
                if(!vis[dS]){
                    vis[dS]=1;
                    q.push(dS);
                }
            }
        }
    }
    printf("%lld\n",f[0]);
}
int main()
{
//    freopen("data.in","r",stdin);
//    freopen("my.out","w",stdout);
    int T;
    scanf("%d",&T);
    for(int i=1;i<=T;i++){
        printf("Case %d: ",i);
        solve();
    }
    return 0;
}