高斯消元解XOR方程组
View Code
srO ZYF Orz
膜拜ZYF……
1 /**************************************************************
2 Problem: 2844
3 User: Tunix
4 Language: C++
5 Result: Accepted
6 Time:252 ms
7 Memory:2052 kb
8 ****************************************************************/
9
10 //BZOJ 2844
11 //srO ZYF Orz
12 #include<cstdio>
13 #include<cstring>
14 #include<cstdlib>
15 #include<iostream>
16 #include<algorithm>
17 #define rep(i,n) for(int i=0;i<n;++i)
18 #define F(i,j,n) for(int i=j;i<=n;++i)
19 #define D(i,j,n) for(int i=j;i>=n;--i)
20 using namespace std;
21 void read(int &v){
22 v=0; int sign=1; char ch=getchar();
23 while(ch<'0'||ch>'9'){ if (ch=='-') sign=-1; ch=getchar();}
24 while(ch>='0'&&ch<='9'){ v=v*10+ch-'0'; ch=getchar();}
25 v*=sign;
26 }
27 /******************tamplate*********************/
28 const int N=100010,MOD=10086;
29 int n,m,k,a[N],b[N];
30 void gauss(){
31 k=n;
32 F(i,1,n){
33 F(j,i+1,n) if (a[j]>a[i]) swap(a[i],a[j]);
34 if (!a[i]) {k=i-1; break;}
35 D(j,30,0) if (a[i]>>j & 1){
36 b[i]=j;
37 F(x,1,n) if (x!=i && a[x]>>j&1) a[x]^=a[i];
38 break;
39 }
40 }
41 }
42 inline int pow(int x,int y){
43 int t=1;
44 for(;y;y>>=1,x=x*x%MOD)
45 if (y&1) t=t*x%MOD;
46 return t;
47 }
48
49 int main(){
50 read(n);
51 F(i,1,n) read(a[i]);
52 read(m);
53 gauss();
54 int ans=1;
55 F(i,1,k) if (m>>b[i]&1){
56 m^=a[i];
57 ans=(ans+pow(2,n-i))%MOD;
58 }
59 printf("%d\n",ans);
60 return 0;
61 }
62
