用高斯列主元消去法求解线性方程组
用高斯列主元消去法方程组
2x1+2x2+3x3=3
4x1+7x2+7x3=1
-2x1+4x2+5*x3=-7
#include<stdio.h>
#include<math.h>
#include<string.h>
#define
N 3
void
printfnum(double a[N][N],double b[N])//显示
{
for(int i=0;i<N;i++)
{
for(int j=0;j<N;j++)
{
printf("%f,",a[i][j]);
}
printf("%f\n",b[i]);
}
}
void
printfresult(double x[N])
{
for(int i=0;i<N;i++)
{
printf("x[%d]=%f\n",i,x[i]);
}
}
void
main()
{
double a[N][N]={
{2,2,3},{4,7,7},{-2,4,5}};
double b[N]={3,1,-7};
double t=0,num1=0,num2=0,m=0,n,x[N]={0,0,0};
printf("初始值:\n");printfnum(a,b);
for(int j=0;j<N;j++)
{
t=fabs(a[j][j]);
m=j;
int i;
for(i=j;i<N;i++)//列主元素
{
if(fabs(a[i][j])>t)//交换两行
{