POJ 1830 高斯消元

#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<vector>
#include<map>
using namespace std;

#pragma comment(linker, "/STACK:102400000,102400000")
#define ls i<<1
#define rs ls | 1
#define mid ((ll+rr)>>1)
#define pii pair<int,int>
#define MP make_pair

typedef long long LL;
const long long INF = 1e18;
const double Pi = acos(-1.0);
const int N = 1e5+10, M = 1e6+11, inf = 2e9, mod = 1e6+3;

int a[330][330], n;
int gauss() {
        int i,j;
        for(i = 0, j = 0; j < n && i < n; ++j) {
            int k = i;
            for(; k < n; ++k) if(a[k][j]) break;
            if(a[k][j]) {
                for(int u = 0; u <= n; ++u) swap(a[k][u],a[i][u]);
                for(int u = i + 1; u < n; ++u) {
                    if(a[u][j]) for(int kk = 0; kk <= n; ++kk)
                        a[u][kk] ^= a[i][kk];
                }
                ++i;
            }
        }
        for(j = i; j < n; ++j) {
            if(a[j][n]) return -1;
        }
        return 1LL << (n - i);
}
int main() {
        int k;
        scanf("%d",&k);
        while(k--) {
            memset(a,0,sizeof(a));
            scanf("%d",&n);
            for(int i = 0; i < n; ++i) scanf("%d",&a[i][n]);
            for(int i = 0; i < n; ++i) {
                int x;
                scanf("%d",&x);
                a[i][n] ^= x;
                a[i][i] = 1;
            }
            int u,v;
            while(scanf("%d%d",&u,&v) && u + v) {
                a[v-1][u-1] = 1;
            }
            int ans = gauss();
            if(ans == -1) puts("Oh,it‘s impossible~!!");else
                printf("%d\n",ans);
        }
        return 0;
}