Poj1830开关问题，高斯消元

#include<iostream>
#include<cstdio>
#include<cstring>
#include<map>
#include<vector>
#include<stdlib.h>
using namespace std;

int Map[100][100];

int gauss(int equ, int var)
{
int k; int col;
for (k = 0, col = 0; k < equ&&col < var; k++, col++){
int kk = k;
for (int i = k + 1; i < equ; i++){
if (Map[i][col]>Map[kk][col])kk = i;
}
if (kk != k){
for (int j = k; j <= var; j++)
swap(Map[k][j], Map[kk][j]);
}
if (Map[k][col] == 0){
k--; continue;
}
for (int i = k + 1; i < equ; i++){
if (Map[i][col]){
for (int j = col; j <= var; j++){
Map[i][j] ^= Map[k][j];
}
}
}
}
for (int i = k; i < equ; i++){
if (Map[i][col]) return -1;
}
return col - k;
}
int main()
{
int k; int n;
int a[100], b[100];
int c; int d;
cin >> k;
while (k--){
cin >> n;
memset(Map, 0, sizeof(Map));
for (int i = 0; i < n; i++)
scanf("%d", &a[i]);
for (int i = 0; i < n; i++)
scanf("%d", &b[i]);
for (int i = 0; i < n; i++)
a[i] = (a[i] ^ b[i]);
for (int i = 0; i < n; i++)
Map[i]
= a[i];
for(int i =0;i<n;i++)
Map[i][i] = 1;
while (cin >> c >> d, c || d){
c--;d--;
Map[d][c] = 1;
}
int ans = 1;
int t = gauss(n, n);
if(t==-1){
cout<<"Oh,it's impossible~!!"<<endl;
continue;
}
for (int i = 0; i < t; i++)
ans *= 2;
cout << ans << endl;
}
return 0;
}