Wa on #3,#7,#11

都是无穷解判成无解

#include<bits/stdc++.h>
/*
#pragma GCC optimize(3)
#pragma GCC optimize("Ofast,no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("inline")
#pragma GCC optimize("-fgcse")
#pragma GCC optimize("-fgcse-lm")
#pragma GCC optimize("-fipa-sra")
#pragma GCC optimize("-ftree-pre")
#pragma GCC optimize("-ftree-vrp")
#pragma GCC optimize("-fpeephole2")
#pragma GCC optimize("-ffast-math")
#pragma GCC optimize("-fsched-spec")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("-falign-jumps")
#pragma GCC optimize("-falign-loops")
#pragma GCC optimize("-falign-labels")
#pragma GCC optimize("-fdevirtualize")
#pragma GCC optimize("-fcaller-saves")
#pragma GCC optimize("-fcrossjumping")
#pragma GCC optimize("-fthread-jumps")
#pragma GCC optimize("-funroll-loops")
#pragma GCC optimize("-fwhole-program")
#pragma GCC optimize("-freorder-blocks")
#pragma GCC optimize("-fschedule-insns")
#pragma GCC optimize("inline-functions")
#pragma GCC optimize("-ftree-tail-merge")
#pragma GCC optimize("-fschedule-insns2")
#pragma GCC optimize("-fstrict-aliasing")
#pragma GCC optimize("-fstrict-overflow")
#pragma GCC optimize("-falign-functions")
#pragma GCC optimize("-fcse-skip-blocks")
#pragma GCC optimize("-fcse-follow-jumps")
#pragma GCC optimize("-fsched-interblock")
#pragma GCC optimize("-fpartial-inlining")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("-freorder-functions")
#pragma GCC optimize("-findirect-inlining")
#pragma GCC optimize("-fhoist-adjacent-loads")
#pragma GCC optimize("-frerun-cse-after-loop")
#pragma GCC optimize("inline-small-functions")
#pragma GCC optimize("-finline-small-functions")
#pragma GCC optimize("-ftree-switch-conversion")
#pragma GCC optimize("-foptimize-sibling-calls")
#pragma GCC optimize("-fexpensive-optimizations")
#pragma GCC optimize("-funsafe-loop-optimizations")
#pragma GCC optimize("inline-functions-called-once")
#pragma GCC optimize("-fdelete-null-pointer-checks")
#pragma GCC optimize("-fdelete-null-pointer-checks,inline-functions-called-once,-funsafe-loop-optimizations,-fexpensive-optimizations,-foptimize-sibling-calls,-ftree-switch-conversion,-finline-small-functions,inline-small-functions,-frerun-cse-after-loop,-fhoist-adjacent-loads,-findirect-inlining,-freorder-functions,no-stack-protector,-fpartial-inlining,-fsched-interblock,-fcse-follow-jumps,-fcse-skip-blocks,-falign-functions,-fstrict-overflow,-fstrict-aliasing,-fschedule-insns2,-ftree-tail-merge,inline-functions,-fschedule-insns,-freorder-blocks,-fwhole-program,-funroll-loops,-fthread-jumps,-fcrossjumping,-fcaller-saves,-fdevirtualize,-falign-labels,-falign-loops,-falign-jumps,unroll-loops,-fsched-spec,-ffast-math,Ofast,inline,-fgcse,-fgcse-lm,-fipa-sra,-ftree-pre,-ftree-vrp,-fpeephole2",3)
*/
using namespace std;
typedef long long ll;
namespace IO{
	char buf[1 << 20], *p1 = buf, *p2 = buf;
	#define getchar() (p1 == p2 && (p2 = (p1 = buf) + \
		fread(buf, 1, 1 << 20, stdin), p1 == p2) ? EOF : *p1++)
	inline ll read(){
		ll x = 0,h = 1;
		char ch = getchar();
		while(!(ch=='-'||('0'<=ch&&ch<='9'))) ch = getchar();
		if(ch=='-') h = -1;
		else x = ch-'0';
		ch = getchar();
		while('0'<=ch&&ch<='9'){
			x = x*10+ch-'0';
			ch = getchar();
		}
		return x*h;
	}
	inline ll digread(){
		char ch = getchar();
		while(!('0'<=ch&&ch<='9')) ch = getchar();
		return ch-'0';
	}
	inline char readCH(){
		char ch = getchar();
		while(!(ch=='x')) ch = getchar();
		return ch;
	}
	inline void print(ll x){
		if(x>9) print(x/10);
		putchar(x%10+'0');
	}
	inline void write(ll x){
		if(x<0) putchar('-'),x = -x;
		print(x);
	}
}
using namespace IO;
namespace MathLab{
	inline ll ksm(ll _x,ll _k,ll _mod){
		ll _res = 1;
		while(_k){
			if(_k&1) _res = _res*_x%_mod;
			_x = _x*_x%_mod;
			_k>>=1;
		}
		return _res;
	}
	inline ll phi(ll _x){
		ll _res = _x;
		for(ll _i = 2; _i*_i <= _x; _i++){
			if(_x%_i==0){
				while(_x%_i==0) _x/=_i;
				_res = _res*(_i-1)/_i;
			}
		}
		if(_x>1) _res = _res*(_x-1)/_x;
		return _res;
	}
	inline ll gcd(ll _x,ll _y){
		return _y?gcd(_y,_x%_y):_x;
	}
	inline ll lcm(ll _x,ll _y){
		return _x*_y/gcd(_x,_y);
	}
	inline bool IsPrime(ll _x){
		if(_x<=1) return 0;
		for(ll _i = 2; _i*_i <= _x; _i++) if(_x%_i==0) return 1;
		return 0;
	}
	inline void AddMod(ll &_x,ll _y,ll _mod){
		_x = (_x+_y>=_mod?_x+_y-_mod:_x+_y);
	}
	inline void MulMod(ll &_x,ll _y,ll _mod){
		_x = _x*_y%_mod;
	}
	inline ll GetMid(ll _x){
		return (_x&1LL)?((_x>>1LL)+1LL):(_x>>1LL);
	}
	inline ll GetFac(ll _x,ll _mod){
		return _x?GetFac(_x-1,_mod)*_x%_mod:1LL;
	}
	inline ll Inv(ll _x,ll _mod){
		return ksm(_x,_mod-2,_mod);
	}
	
}
#define File(name)                     \
    freopen(#name ".in", "r", stdin);  \
    freopen(#name ".out", "w", stdout);
#define ERR assert(0)
#define RunTime ((double)clock()/CLOCKS_PER_SEC)
/*
有时候程序没反应就把 IO 里面重定义 getchar 删掉 
-std=c++11  -Wall -Wextra -Wl,--stack=102400000000 -fno-ms-extensions
找不出来哪错了要检查 RE 问题，比如数组开小了，越界，函数返回值
用 long long TLE 可以尝试换成 int
对 vector 进行修改时，要 for(auto &v : vec) v++。必须加 &
n 行 m 列的矩阵先从左到右在从上到下编号，第 i 行 j 列是 (i-1)*m+j
网络流建图正边反边一定连着建
*/
namespace YYZ{
	const ll N = 310;
	const double eps = 1e-7;
	ll n,tot = 1;
	double gs[N][N];
	double res[N];
	double dabs(double x){return (x>0.0?x:-x);}
	void main(){
		n = read();for(ll i = 1; i <= n; i++) for(ll j = 1; j <= n+1; j++) gs[i][j] = read();
		for(ll i = 1; i <= n; i++){
			ll r = i;
			for(ll j = i+1; j <= n; j++){
				if(dabs(gs[r][i])<dabs(gs[j][i])) r = j;
			}
			if(dabs(gs[r][i])<eps) continue;
			if(i!=r) swap(gs[i],gs[r]);
			double div = gs[i][i];
			for(ll j = i; j <= n+1; j++) gs[i][j]/=div;
			for(ll j = i+1; j <= n; j++){
				div = gs[j][i];
				for(ll k = i; k <= n+1; k++){
					gs[j][k]-=gs[i][k]*div;
				}
			}
			tot++;
		}
		//printf("%lld\n",tot);
		//for(ll i = 1; i <= n; i++){
		//for(ll j = 1; j <= n+1; j++) printf("%.2lf ",gs[i][j]);
		//puts("");
		//}
		res[n] = gs[n][n+1];
		for(ll i = n-1; i >= 1; i--){
			res[i] = gs[i][n+1];
			for(ll j = i+1; j <= n; j++) res[i]-=gs[i][j]*res[j];
		}
		if(tot<=n){
			for(ll i = tot; i <= n; i++) if(dabs(gs[i][n+1])>eps){puts("-1");return;}
			puts("0");return;
		}
		for(ll i = 1; i <= n; i++) printf("x%lld=%.2lf\n",i,res[i]);
	}
}
int main(){
	ll T = 1;
	while(T--) YYZ::main();
	fprintf(stderr, "TIME:%.3lf s\n", RunTime);
	return 0;
}
/*

*/