Interchange any two rows in a matrix

Posted on Apr 26, 2020

C program to interchange any two rows in a matrix.

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 interchange_row(int mat[MAX][MAX], int row, int col, int row1, int row2)
{
    int i, j, temp;

    for(i=0;i<col;i++)
    {
        temp = mat[row1][i];
        mat[row1][i] = mat[row2][i];
        mat[row2][i] = temp;
    }
}

void main()
{
    int mat[MAX][MAX];
    int row, col, row1, row2;

    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 the matrix\n");
    read_matrix(mat, row, col);
    printf("Enter the indexes of the rows to be interchanged (0 to %d)\t:",row-1);
    scanf("%d%d",&row1, &row2);

    printf("\nMatrix entered is\n");
    print_matrix(mat, row, col);

    interchange_row(mat, row, col, row1, row2);

    printf("\nMatrix after interchanging of rows\n");
    print_matrix(mat, row, col);

    getch();
}

Output

Enter the number of rows        :3
Enter the number of columns     :4
Enter the elements of the matrix
Element [0][0]  :1
Element [0][1]  :2
Element [0][2]  :3
Element [0][3]  :4
Element [1][0]  :5
Element [1][1]  :6
Element [1][2]  :7
Element [1][3]  :8
Element [2][0]  :9
Element [2][1]  :10
Element [2][2]  :11
Element [2][3]  :12
Enter the indexes of the rows to be interchanged (0 to 2)       :0
2

Matrix entered is
1       2       3       4
5       6       7       8
9       10      11      12

Matrix after interchanging of rows
9       10      11      12
5       6       7       8
1       2       3       4