Addition and subtraction of two matrices

Posted on Apr 25, 2020

C program to find Addition and subtraction of two matrices.

Two matrices may be added or subtracted only if they have the same dimension; i.e. they must have the same number of rows and columns.

Addition or subtraction is accomplished by adding or subtracting corresponding elements. For example,

Program

#include<stdio.h>
#include<conio.h>
#define MAX 10

void read_matrix(int mat[MAX][MAX], int row, int col)
{
    int i, j;
    for(i=0;i<row;i++)
    {
        for(j=0;j<col;j++)
        {
            printf("Element [%d][%d]\t:",i,j);
            scanf("%d",&mat[i][j]);
        }
    }
}

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

void add_matrix(int mat1[MAX][MAX], int mat2[MAX][MAX], int add[MAX][MAX], int row, int col)
{
    int i, j;
    for(i=0;i<row;i++)
    {
        for(j=0;j<col;j++)
        {
            add[i][j] = mat1[i][j] + mat2[i][j];
        }
    }
}

void sub_matrix(int mat1[MAX][MAX], int mat2[MAX][MAX], int sub[MAX][MAX], int row, int col)
{
    int i, j;
    for(i=0;i<row;i++)
    {
        for(j=0;j<col;j++)
        {
            sub[i][j] = mat1[i][j] - mat2[i][j];
        }
    }
}

void main()
{
    int mat1[MAX][MAX], mat2[MAX][MAX], add[MAX][MAX], sub[MAX][MAX];
    int row, col;

    printf("Enter the number of rows\t:");
    scanf("%d",&row);
    printf("Enter the number of columns\t:");
    scanf("%d",&col);

    printf("Enter the elements of first matrix\n");
    read_matrix(mat1, row, col);
    printf("Enter the elements of second matrix\n");
    read_matrix(mat2, row, col);

    printf("\nFirst matrix entered is\n");
    print_matrix(mat1, row, col);
    printf("\nSecond matrix entered is\n");
    print_matrix(mat2, row, col);

    add_matrix(mat1, mat2, add, row, col);
    sub_matrix(mat1, mat2, sub, row, col);

    printf("\nMatrix after addition\n");
    print_matrix(add, row, col);
    printf("\nMatrix after subtraction\n");
    print_matrix(sub, row, col);

    getch();
}

Output

Enter the number of rows        :3
Enter the number of columns     :4
Enter the elements of first matrix
Element [0][0]  :1
Element [0][1]  :2
Element [0][2]  :3
Element [0][3]  :4
Element [1][0]  :4
Element [1][1]  :3
Element [1][2]  :2
Element [1][3]  :1
Element [2][0]  :5
Element [2][1]  :6
Element [2][2]  :7
Element [2][3]  :8
Enter the elements of second matrix
Element [0][0]  :8
Element [0][1]  :7
Element [0][2]  :6
Element [0][3]  :5
Element [1][0]  :9
Element [1][1]  :8
Element [1][2]  :6
Element [1][3]  :5
Element [2][0]  :4
Element [2][1]  :3
Element [2][2]  :5
Element [2][3]  :2

First matrix entered is
1       2       3       4
4       3       2       1
5       6       7       8

Second matrix entered is
8       7       6       5
9       8       6       5
4       3       5       2

Matrix after addition
9       9       9       9
13      11      8       6
9       9       12      10

Matrix after subtraction
-7      -5      -3      -1
-5      -5      -4      -4
1       3       2       6