hdu3949:XOR
传送门:http://acm.hdu.edu.cn/showproblem.php?pid=3949
一个讲的比较好的博客:http://m.blog.csdn.net/blog/wdcjdtc/38300217
Orz hzwer:http://hzwer.com/5491.html
思路:为什么我搜线性基什么也没搜到呢..
用高斯消元维护线性基,然后....就是代码了
#include<cstdio> #include<cstring> #include<iostream> #include<algorithm> const int maxn=10010; using namespace std; typedef long long ll; int T,n,m,tot;ll a[maxn],bin[65],x;char ch;bool zero; void read(ll &x){ for (ch=getchar();!isdigit(ch);ch=getchar()); for (x=0;isdigit(ch);ch=getchar()) x=x*10+ch-'0'; } void gauss(){ tot=zero=0; for (int i=60;i>=0;i--){ int j=tot+1; for (;!(bin[i]&a[j])&&j<=n;j++); if (j>n) continue; swap(a[++tot],a[j]); for (int j=1;j<=n;j++) if (j!=tot&&(a[j]&bin[i])) a[j]^=a[tot]; } if (tot!=n) zero=1; } ll query(ll x){ ll res=0;x-=zero; if (!x) return 0; if (x>=bin[tot]) return -1; for (int i=1;i<=tot;i++) if (x&bin[tot-i]) res^=a[i]; return res; } int main(){ bin[0]=1;for (int i=1;i<=62;i++) bin[i]=bin[i-1]<<1; scanf("%d",&T); for (int i=1;i<=T;i++){ printf("Case #%d:\n",i); memset(a,0,sizeof(a)),scanf("%d",&n); for (int j=1;j<=n;j++) read(a[j]); gauss(),scanf("%d",&m); for (int j=1;j<=m;j++) read(x),printf("%lld\n",query(x)); } return 0; }