Singularity of a matrix using Cramer's Rule in C

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/* Testing singularity of a matrix  */

#include<stdio.h>
int i, j;
float mat[10][10];
float mat1[10][10];
void display( int, int);
void input( int, int);
float Singular_Matrix(int, int);

/* Output function */

void display( int row, int col)
{
    for(i = 0; i < row; i++)
    {
        for(j = 0; j < col; j++)
        {
            printf("  %f", mat[i][j]);
        }
        printf("\n");
    }
}

/* Input function */
void input( int row, int col)
{
    for(i = 0 ; i< row; i++)
    {
        for(j = 0 ;  j<col; j++)
        {
            printf("Input Value for : %d: %d: ", i+1, j+1);
            scanf("%f", &mat[i][j]);
        }
    }
}

/* Find Determinant using Cramer's rule */

float Singular_Matrix( int row1, int col1)
{
    int i, j, k, l;
    float sum=0, psum=0, partial=0, nsum=0;
    if(row1 == col1)
    {
        printf("\n Number rows  = Number of cols");
        printf("\n Singular Test is possible\n");

        if(row1 < 3)
        {
            sum = mat[0][0]*mat[1][1] - mat[0][1]*mat[1][0];
            return(sum);
        }
        else
        {
            for(k = 0; k <row1; k++)
                for(j = 0; j < row1; j++)
                    mat1[k][j] = mat[k][j];

            for(k = 0; k <row1; k++)
                for(j = row1; j < (2*row1-1); j++)
                    mat1[k][j] = mat1[k][j-row1];

            for(l = 0; l <row1; l++)
            {
                partial = 1;
                for(i = 0; i <row1; i++)
                {
                    partial *= mat1[i][i+l];
                }
                psum += partial;
            }

            for(l = row1-1; l < ( 2*row1 -1); l++)
            {
                partial = 1;
                for(i =0; i < row1; i++)
                {
                    partial *=mat1[i][l-i];
                }
                nsum += partial;
            }
            sum = psum - nsum ;
            return(sum);
        }
    }

    else
        printf("\n Check about singularity is not possible");

    return 0;
}

/* main function */

void main()
{
    float Determinant;
    int r,c;
    printf("\n Input the number of rows:");
    scanf("%d", &r);
    printf(" Input the number of cols:");
    scanf("%d", &c);
    input(r, c);
    printf("\n Entered Two Dimensional array is as follows:\n");
    display(r, c);
    Determinant = Singular_Matrix(r, c);
    printf("\n Determinant is : %d", Determinant);

    if(Determinant == 0)
        printf("\n The Above matrix is Singular");
    else
        printf("\n Above matrix is not singular");
}

Posted in: Programming in C