# Gauss Jordan Method Using C Programming

Earlier in Gauss Jordan Method Algorithm and Gauss Jordan Method Pseudocode , we discussed about an algorithm and pseudocode for solving systems of linear equation using Gauss Jordan Method. In this tutorial we are going to implement this method using C programming language.

## Complete Program for Gauss Jordan method using C Programming Language

``````
#include<stdio.h>
#include<conio.h>
#include<math.h>

#define SIZE 10

int main()
{
float a[SIZE][SIZE], x[SIZE], ratio;
int i,j,k,n;
clrscr();
/* Inputs */
/* 1. Reading number of unknowns */
printf("Enter number of unknowns: ");
scanf("%d", &n);
/* 2. Reading Augmented Matrix */
printf("Enter coefficients of Augmented Matrix:\n");
for(i=1;i<=n;i++)
{
for(j=1;j<=n+1;j++)
{
printf("a[%d][%d] = ",i,j);
scanf("%f", &a[i][j]);
}
}
/* Applying Gauss Jordan Elimination */
for(i=1;i<=n;i++)
{
if(a[i][i] == 0.0)
{
printf("Mathematical Error!");
exit(0);
}
for(j=1;j<=n;j++)
{
if(i!=j)
{
ratio = a[j][i]/a[i][i];
for(k=1;k<=n+1;k++)
{
a[j][k] = a[j][k] - ratio*a[i][k];
}
}
}
}
/* Obtaining Solution */
for(i=1;i<=n;i++)
{
x[i] = a[i][n+1]/a[i][i];
}
/* Displaying Solution */
printf("\nSolution:\n");
for(i=1;i<=n;i++)
{
printf("x[%d] = %0.3f\n",i, x[i]);
}
getch();
return(0);
}
``````

## Output

```Enter number of unknowns: 4
Enter Coefficients of Augmented Matrix:
a[1]1]= 1
a[1]2]= 2
a[1]3]= 3
a[1]4]= -1
a[1]5]= 10
a[2]1]= 2
a[2]2]= 3
a[2]3]= -3
a[2]4]= -1
a[2]5]= 1
a[3]1]= 2
a[3]2]= -1
a[3]3]= 2
a[3]4]= 3
a[3]5]= 7
a[4]1]= 3
a[4]2]= 2
a[4]3]= -4
a[4]4]= 3
a[4]5]= 2

Solution:
x[1] = 1.000
x[2] = 2.000
x[3] = 2.000
x[4] = 1.000
```