1234.c

华中科技大学计算机学院《计算方法》课件（含C源代码）。通过它可以学习求解复杂数学问题的基本方法以及编程实现。

#include<stdio.h>
#include<stdlib.h>
#include<conio.h>
#include<math.h>
#define PRECISION 0.000001
static int seed=10000+1.016*1000;
unsigned int max=32767;
unsigned int m=6,n=7;
static float a[80][80];

void setmatrixwith (int seed)
{
  int i,j,k;
  float x;
  srand (seed);
  for (i=1;i<=1000;++i) k=rand();
  for (i=1;i<=m;++i)
    for (j=1;j<=n;++j)
    {
      k=rand();
      x=(float) k;
      a[i][j]=x*20/max-10;
    }
  return;
}

void printmatrix ()
{
  int i,j;
  printf ("\n");
  for (i=1;i<=m;++i)
  {
    printf ("\n");
    for (j=1;j<=n;++j)
    printf ("%10.4f",a[i][j]);
  }
  getch();
}
void MatrixOneColumnOutput(float a[][80],int n,int k)
{
 int i,j;
 for(i=1;i<=n;++i)
     {
      printf ("\n");
      for(j=1;j<=k;++j)
      printf ("%10.4f",a[i][j]);
     }
}
int UpTriangle(float U[7][8],int n)
{
 int i,j;
 for(i=n;i>0;--i)
    {
     if(fabs(U[i][i])<PRECISION)
     return 1;
     for(j=i+1;j<=n;++j)
     U[i][n+1]-=U[i][j]*U[j][n+1];
     U[i][n+1]/=U[i][i];
    }
 return 0;
}
int GassElimination_column_select(float a[][80],int n)
{
 int i,j,k;
 float ftmp;
 for(i=1;i<n;++i)
    {
     if(fabs(a[i][i])<PRECISION)
     return 1;
     for(j=i+1;j<=n;++j)
     for(k=i+1;k<=n+1;++k)
     a[j][k]-=a[i][k]*a[j][i]/a[i][i];
    }
 UpTriangle(a,n);
 return 0;
}
void main()
{
 setmatrixwith (seed);
 printmatrix ();
 if(GassElimination_column_select(a,m))
 printf("\nGass Failed!");
 else
 {
  printf("\nOutput Solution:\n");
  MatrixOneColumnOutput(a,m,n);
 }
 printf("\n\n007Press any key to quit!\n");
 getch();
}