#include
     
      #define re return#define inc(i,l,r) for(int i=l;i<=r;++i)#define dec(i,l,r) for(int i=l;i>=r;--i)const double EPS=1e-7;char buf[1<<21],*p1,*p2;inline int getc(){re p1==p2 and (p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++;}template
      
       inline void rd(T&x){    char c;bool f=0;    while((c=getc())<'0'||c>'9')if(c=='-')f=1;    x=c^48;    while((c=getc())>='0' and c<='9')x=x*10+(c^48);    if(f)x=-x;}using namespace std;double a[105][105],ans[105];int n;int main(){//    freopen("in.txt","r",stdin);    rd(n);    inc(i,1,n)inc(j,1,n+1)rd(a[i][j]);             inc(i,1,n){        int r=i;        if(fabs(a[r][r])
      
     

线性函数，加减消元