Matrix Operations

/* Subhranath Chunder - Matrix Operations */

/* A program to implement the following operation on two matrices:
   a. Addition
   b. Multiplication
   c. Transposition
   d. Determinant */

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

/* Function declarations */
void print(int[][100],int,int);
void add(int[][100],int,int,int[][100],int,int);
void multiply(int[][100],int,int,int[][100],int,int);
void transpose(int[][100],int,int);
int determinant(int[][100],int);

/* Main Program */
void main()
{
   int inp1[100][100],inp2[100][100],m1,n1,m2,n2,i,j,option=0;
   clrscr();

   /* The values of the matrices are accepted */
   printf("Enter the dimensions of the first matrix in the form mXn: ");
   scanf("%dX%d",&m1,&n1);
   printf("Enter the values of the first matrix:\n");
   for(i=0;i<m1;++i)
   {
      for(j=0;j<n1;++j)
         scanf("%d",&inp1[i][j]);
   }
   printf("\n\nEnter the dimensions of the second matrix in the form mXn: ");
   scanf("%dX%d",&m2,&n2);
   printf("Enter the values of the second matrix:\n");
   for(i=0;i<m2;++i)
   {
      for(j=0;j<n2;++j)
         scanf("%d",&inp2[i][j]);
   }

   /* Main Menu - where the user chooses what he wants to do */
   while(option==0)
   {
      clrscr();
      printf("You can perform the following operations on the matrices:\n\n1. Addition\n2. Multiplication\n3. Transposition\n4. Determinant\n5. Exit\n\nEnter Choice: ");
      scanf("%d",&option);
      clrscr();

      /* Performs addition on the two matrices */
      if(option==1)
      {
         add(inp1,m1,n1,inp2,m2,n2);
         getch();
      }

      /* Performs multiplication on the two matrices */
      if(option==2)
      {
         multiply(inp1,m1,n1,inp2,m2,n2);
         getch();
      }

      /* Transposes a specified matrix */
      while(option==3)
      {
         printf("Which matrix would you like to transpose?\n\n1. First Matrix\n2. Second Matrix\n\nEnter Choice: ");
         scanf("%d",&option);
         clrscr();
         if(option==1 || option==2)
         {
            if(option==1)
               transpose(inp1,m1,n1);
            if(option==2)
               transpose(inp2,m2,n2);
            getch();
         }
         else
            option=3;
      }

      /* Finds the determinant of a specified matrix */
      while(option==4)
      {
         printf("Find the determinant of which matrix?\n\n1. First Matrix\n2. Second Matrix\n\nEnter Choice: ");
         scanf("%d",&option);
         clrscr();
         if(option==1 || option==2)
         {
            if(option==1)
            {
               if(m1==n1)
                  printf("The determinant of the matrix is: %d",determinant(inp1,m1));
               else
                  printf("The derterminant of the matrix cannot be determined.");
            }
            if(option==2)
            {
               if(m2==n2)
                  printf("The determinant of the matrix is: %d",determinant(inp2,m2));
               else
                  printf("The derterminant of the matrix cannot be determined.");
            }
            getch();
         }
         else
            option=4;
      }

      /* Exits the program */
      if(option==5)
         break;

      /* Returns the control back to main menu */
      option=0;
   }
}
/* Main Program Ends */

/* Performs addition on the two specified matrices */
void add(int arr1[][100],int m1,int n1,int arr2[][100],int m2,int n2)
{
   int arr3[100][100],i,j;
   if(m1==m2 && n1==n2)
   {
      for(i=0;i<m1;++i)
      {
         for(j=0;j<n1;++j)
            arr3[i][j]=arr1[i][j]+arr2[i][j];
      }
      printf("The sum of the two matrices is given below:\n\n");
      print(arr3,m1,n1);
   }
   else
      printf("The matrices cannot be added");
}

/* Performs multiplication on the two specified matrices */
void multiply(int arr1[][100],int m1,int n1,int arr2[][100],int m2,int n2)
{
   int arr3[100][100],i,j,k;
   if(n1==m2)
   {
      for(i=0;i<m1;++i)
      {
         for(j=0;j<n2;++j)
         {
            arr3[i][j]=0;
            for(k=0;k<n1;++k)
               arr3[i][j]+=arr1[i][k]*arr2[k][j];
         }
      }
      printf("The product of the two matrices is given below:\n\n");
      print(arr3,m1,n2);
   }
   else
      printf("The matrices cannot be multiplied");
}

/* Transposes a specified matrix */
void transpose(int arr[][100],int m,int n)
{
   int arr2[100][100],i,j;
   for(i=0;i<m;++i)
   {
      for(j=0;j<n;++j)
         arr2[j][i]=arr[i][j];
   }
   printf("The transpose of the matrix is given below:\n\n");
   print(arr2,n,m);
}

/* Finds the determinant of a specified matrix */
int determinant(int arr[][100],int n)
{
   int temp[100][100],a,b,result=0,i,j,k;
   if(n==1)
      return(arr[0][0]);
   else
   {
      for(i=0;i<n;++i)
      {
         a=0;
         b=0;
         for(j=1;j<n;++j)
         {
            for(k=0;k<n;++k)
            {
               if(k!=i)
               {
                  temp[a][b]=arr[j][k];
                  ++b;
               }
            }
            b=0;
            ++a;
         }
         result+=arr[0][i]*determinant(temp,n-1)*pow(-1,i);
      }
   }
   return result;
}

/* Prints a matrix of specified dimension */
void print(int arr[][100],int m,int n)
{
   int i,j;
   for(i=0;i<m;++i)
   {
      for(j=0;j<n;++j)
         printf("%d\t",arr[i][j]);
      printf("\n");
   }
}