C++编程解决线性方程组

#include "LinearEqu.h" #include <iostream> #include <cmath> using namespace std; LinearEqu::LinearEqu(int size/* = 2*/):Matrix(size) { sums=new double[size]; solution=new double[size]; } LinearEqu::~LinearEqu() { delete[] sums; delete[] solution; } void LinearEqu::SetLinearEqu(const double *a,const double *b) { SetMatrix(a); for(int i=0;i<getsize();i++) sums[i]=b[i]; } void LinearEqu::ShowLinearEqu()const { cout<<"The line eqution is :"<<endl; for(int i=0;i<getsize();i++) { for(int j=0;j<getsize()-1;j++) cout<<element(i,j)<<" x["<<j<<"] + "; cout<<element(i,getsize()-1)<<" x["<<getsize()-1<<"]"; cout<<"="<<sums[i]<<endl; } } void LinearEqu::Showsolution()const{ cout<<"The result is :"<<endl; for(int i=0;i<getsize();i++) cout<<"x["<<i<<"]="<<solution[i]<<endl; } void swap(double &e,double &f){ double m=e; e=f; f=m; } bool LinearEqu::Solve(){ int *js=new int[getsize()]; for(int k=0;k<getsize()-1;k++){ int is; double max=0; for(int i=k;i<getsize();i++) for(int j=0;j<getsize();j++) { double t=fabs(element(i,j)); if(t>max){ max=t; js[k]=j; is=i; } } if(max=0){ delete[]js; return false; } else{ if(js[k]!=k) for(int i=0;i<getsize();i++) swap(element(i,k),element(i,js[k])); if(is!=k){ for(int j=k;j<getsize();j++) swap(element(k,j),element(is,j)); swap(sums[k],sums[is]); } } double major=element(k,k); for(int j=k+1;j<getsize();j++) element(k,j)/=major; sums[k]/=major; for(int i=k+1;i<getsize();i++) { for(int j=k+1;j<getsize();j++) element(i,j)-=element(i,k)*element(k,j); sums[i]-=element(i,k)*sums[k]; } } double d=element(getsize()-1,getsize()-1); if(fabs(d)<1e-15) { delete[]js; return false; } solution[getsize()-1]=sums[getsize()-1]/d; for(int i=getsize()-2;i>=0;i--) { double t=0.0; for(int j=i+1;j<=getsize()-1;j++) t+=element(i,j)*solution[j]; solution[i]=sums[i]-t; } js[getsize()-1]=getsize()-1; for(int k=getsize()-1;k>=0;k--) if(js[k]!=k) swap(solution[k],solution[js[k]]); delete[] js; return true; }