WA on #3,#11,#13

#include <bits/stdc++.h>
using namespace std;
const double eps=1e-7;
int n;
double a[56][56];
void print(){
	for (int i=1;i<=n;i++){
		for (int j=1;j<=n+1;j++){
			printf("%.2lf ",a[i][j]);
		}
		printf("\n");
	}
}
int main(){
	scanf("%d",&n);
	for (int i=1;i<=n;i++){
		for (int j=1;j<=n+1;j++){
			scanf("%lf",&a[i][j]);
		}
	}
	for (int i=1;i<=n;i++){
		for (int j=i;j<=n;j++){
			if (fabs(a[j][i])-fabs(a[i][i])>eps){
				swap(a[i],a[j]);
			}
		}
		if (fabs(a[i][i]-0.0)<eps) continue;
		for (int j=n+1;j>=i;j--){
			a[i][j]=a[i][j]*1.0/a[i][i];
// 			cout<<a[i][j]<<" "<<a[i][i]<<endl;
		}
		for (int j=n;j>=1;j--){
			if (j==i) continue;
			for (int k=i+1;k<=n+1;k++){
//				if (k==i) continue;
				a[j][k]-=a[j][i]*a[i][k];
//				cout<<i<<j<<k<<a[2][2]<<endl;
			}
		}
		for (int j=1;j<=n;j++) if (j!=i) a[j][i]=0;
//		print();
	}
	for (int i=1;i<=n;i++){
		if (fabs(a[i][i]-0.0)<eps){
			if (fabs(a[i][n+1]-0.0)<eps) printf("0");
			else printf("-1");
			return 0;
		}
	}
	for (int i=1;i<=n;i++){
		printf("x%d=%.2lf\n",i,a[i][n+1]);
	}
	return 0;
}