计算机上机报告(5)

3.运行结果

九．Gauss列主元消去法 1.程序代码（C++代码）

#include #include #include

#define max_dimension 20 int n;

static float a[max_dimension][max_dimension]; static float b[max_dimension]; static float x[max_dimension]; void main() {int i; int j; int d; int row; float temp;

float known_items;

float l[max_dimension][max_dimension]; printf(\请输入阶数:\scanf(\printf(\

printf(\请输入系数矩阵的值: \printf(\

for(i=0; i

{ printf(\输入第%d行的值:\ for (j=0; j

scanf(\ }

printf(\}

printf(\请输入常数项的值: \for(i=0; i

for(d=0; d

for(i=d+1; i

{if(fabs(a[i][d])>fabs(a[row][d])) row=i; }

if(row!=d)

{for(j=d; j

temp=b[row]; b[row]=b[d]; b[d]=temp; }

for(i=d+1; i

{l[i][d]=-a[i][d]/a[d][d]; for (j=d; j

{a[i][j]=a[i][j]+a[d][j]*l[i][d]; }

b[i]=b[i]+b[d]*l[i][d]; } }

printf(\

for (i=n-1; i>-1; i--) {known_items=0;

for(j=1; j

{known_items=known_items+a[i][i+j]*x[i+j]; }

x[i]=(b[i]-known_items)/a[i][i]; }

printf(\方程组的根为:\\n\\n\for(i=0; i

printf(\printf(\getch(); }

2.例子

3.运行结果