Thread: Repeated printing of a specific elements-sparse matrix addition?

Hi! Here's my code for addition of two sparse matrices represented as a 3-tuple. The program adds up all elements in sparse matrices A and B and stores it in matrix C except that it repeats some elements. How should the code be modified?

Here's my code:

Code:

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

 
int main(void)
{
  int a[20][3],b[20][3],c[40][3],i,j,k=1,count=0,m; 
   
    printf("Enter non zero elements of s matrix 1:");       //accept matrix A directly in the 3-tuple form
    scanf("%d",&a[0][2]);
    printf("\nEnter matrix:");
     for(i=0;i<=a[0][2];i++)
    {
      for(j=0;j<3;j++)
     {
        scanf("%d%",&a[i][j]);
     }
    }  
        
        
      printf("\nEnter non zero elements of s matrix 2:");   //accept matrix B directly in the 3-tuple form
    scanf("%d",&b[0][2]);
    printf("\nEnter matrix:");
     for(i=0;i<=b[0][2];i++)
    {
      for(j=0;j<3;j++)
     {
        scanf("%d%",&b[i][j]);
     }
    }  
        
        //init all  elements of matrix C to zero(required for the check made below at *)
     
     for(i=0;i<20;i++)
     {
      for(j=0;j<3;j++)
      {
       c[i][j]=0;
      }
     }
     
     
     //copy elements from matrices A and B with the same indices into the corresponding index of C
      
      for(i=1;i<=a[0][2];i++)
      {
       if(a[i][0]==b[i][0] && a[i][1]==b[i][1])
       {
        c[k][0]=a[i][0];
        c[k][1]=a[i][1];
        c[k][2]=a[i][2]+b[i][2];
        count++;
       }
       }
       
       //copy uncommon elements from A to matrix C
       for(i=1;i<=a[0][2];i++)
       {
        LOOP:if(c[k][2]==0)               //* CHECK c[k][2] if it has been modified. If it has, there will be some non zero value.
             {                            //if c[k][2]=0, then there is no data in C at that location.So we may copy current element of A
                                          //into C.. (same for matrix B below..)
              c[k][0]=a[i][0];
              c[k][1]=a[i][1];
              c[k][2]=a[i][2];
              count++;
              k++;
              continue;
              }
              
              else 
              {
               k++;
	       goto LOOP;
               }
       }
       
       
       //copy uncommon from B to matrix C
       k=1;
       for(i=1;i<=b[0][2];i++)
       {
        LOOP2:if(c[k][2]==0)             //* check c[k][2] if it has been modified. If it has, there will be some non zero value.
             {
              c[k][0]=b[i][0];
              c[k][1]=b[i][1];
              c[k][2]=b[i][2];
	      k++;
	      count++;
              continue;
              }
              
              else 
              {
               k++;
	       goto LOOP2;
               }
       }  
    c[0][2]=count;
    c[0][0]=a[0][0];
    c[0][1]=a[0][1];
       
    //print matrix C
   printf("\n\nAddition is:");
   for(i=0;i<=c[0][2];i++)
   {
    printf("\n");
    for(j=0;j<3;j++)
    {    
     printf(" %d ",c[i][j]);
     }
     }
getch();
return 0;
}