#include<bits/stdc++.h>
using namespace std;
const int maxn=106;
const double eps=1e-8;
int n;
double a[maxn][maxn];
double b[maxn];
signed main(){
	scanf("%d",&n);
	for (int i=1;i<=n;i++){
		for (int j=1;j<=n;j++) scanf("%lf",&a[i][j]);
		scanf("%lf",&b[i]);
	}
	for (int i=1,tmp;i<=n;i++){
		// 无解或无数解
		for (tmp=i;tmp<=n;tmp++) if (fabs(a[i][tmp])>eps) break;
		if (tmp==n+1) goto g;
		// 所有 x[i] 均被消去
		for (tmp=i;tmp<=n;tmp++) if (fabs(a[tmp][i])>eps) break;
		if (tmp==n+1) goto g;
		// 若 a[i][i]=0，交换
		if (tmp!=i) for (int j=i;j<=n;j++) swap(a[i][j],a[tmp][j]);
		// 令 a[i][i]=1
		tmp=a[i][i],b[i]/=tmp;
		for (int j=i;j<=n;j++) a[i][j]/=tmp;
		// 令 a[j][i]=0
		for (int j=i+1;j<=n;j++){
			tmp=a[j][i],b[j]-=tmp*b[i];
			for (int k=i;k<=n;k++) a[j][k]-=tmp*a[i][k];
		}
	}
	// 回代求解
	for (int i=n;i>=1;i--) for (int j=1;j<i;j++) b[j]-=a[j][i]*b[i],a[j][i]=0;
	for (int i=1;i<=n;i++) printf("%.2lf\n",b[i]);
	return 0;
	g: printf("No Solution\n");
	return 0;
}

提交记录 0.01的差距 求巨佬帮助