hansang题解

#include<bits/stdc++.h>
using namespace std;
const double eps=1e-8;
int n;
double a[110][110],x[110];
void gauss()
{
	int r=1;
    for(int c=1;c<=n;c++)
    {
    	for(int i=r+1;i<=n;i++)
    	{
    		while( fabs(a[i][c])>eps )
    		{
    			double bs=a[r][c]/a[i][c];
    			for(int j=1;j<=n+1;j++)a[r][j]=a[r][j]-a[i][j]*bs;
    			swap(a[r],a[i]);
    		}
    	}
    	if(fabs(a[r][c])>eps) r++;
    }
	/*
	for(int i=r;i<=n;i++)if(fabs(a[i][n+1])>eps) {printf("no solution\n");return ;}
	if(r<=n) {printf("many solution\n");return ;}
	*/ 
    for(int i=n;i>=1;i--)
	{
		for(int j=i+1;j<=n;j++)a[i][n+1]-=x[j]*a[i][j];
		x[i]=a[i][n+1]/a[i][i];
		if(fabs(x[i])<eps)x[i]=fabs(x[i]);
	}
	for(int i=1;i<=n;i++)printf("%.3lf ",x[i]);
}
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]);
    gauss();
    return 0;
}

hansang题解

#include<bits/stdc++.h>
using namespace std;
const double eps=1e-8;
int n;
double a[110][110],x[110];
void gauss()
{
	int r=1;
    for(int c=1;c<=n;c++)
    {
    	for(int i=r+1;i<=n;i++)
    	{
    		while( fabs(a[i][c])>eps )
    		{
    			double bs=a[r][c]/a[i][c];
    			for(int j=1;j<=n+1;j++)a[r][j]=a[r][j]-a[i][j]*bs;
    			swap(a[r],a[i]);
    		}
    	}
    	if(fabs(a[r][c])>eps) r++;
    }
	/*
	for(int i=r;i<=n;i++)if(fabs(a[i][n+1])>eps) {printf("no solution\n");return ;}
	if(r<=n) {printf("many solution\n");return ;}
	*/ 
    for(int i=n;i>=1;i--)
	{
		for(int j=i+1;j<=n;j++)a[i][n+1]-=x[j]*a[i][j];
		x[i]=a[i][n+1]/a[i][i];
		if(fabs(x[i])<eps)x[i]=fabs(x[i]);
	}
	for(int i=1;i<=n;i++)printf("%.3lf ",x[i]);
}
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]);
    gauss();
    return 0;
}