POJ 2133 暴搜

题意：

思路：
按照题意暴搜

注意 如果目标串==给的串 答案是2

//By SiriurRen
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
int n,k,goal,a[1005],head,tail,q[1000000],vis[1<<16],minn[17],rec[17];
char p;
int main(){
    memset(minn,0x3f,sizeof(minn));
    scanf("%d%d",&k,&n),getchar();
    for(int i=1;i<=k;i++)p=getchar(),goal=goal*2+p-'0';
    for(int i=1;i<=n;i++){
        getchar();
        for(int j=1;j<=k;j++)
            a[i]=a[i]*2+getchar()-'0';
        q[tail++]=a[i];
    }
    while(head<tail){
        int t=q[head++];
        for(int i=1;i<=n;i++)
            if(!vis[t^a[i]])
                vis[t^a[i]]=vis[t]+1,q[tail++]=t^a[i];
    }
    for(int i=0;i<(1<<k);i++){
        if(!vis[i])continue;
        int jy=i^goal,temp=0;
        for(int j=0;j<k;j++)if(jy&(1<<j))temp++;
        if(minn[temp]>vis[i])minn[temp]=vis[i],rec[temp]=i;
        else if(minn[temp]==vis[i])rec[temp]=min(rec[temp],i);
    }
    for(int i=0;i<=k;i++)
        if(minn[i]<=0x3ffffff){
            printf("%d
",minn[i]);
            for(int j=k-1;j>=0;j--)
                printf("%d",rec[i]&(1<<j)?1:0);
            return 0;
        }
}