Q:

# C program to interchange the rows in the matrix

Given a matrix, and we have to interchange the specified rows in the matrix using C program.

Program:

The source code to interchange the rows in the matrix is given below. The given program is compiled and executed using GCC compile on UBUNTU 18.04 OS successfully.

``````// C program to interchange the rows in matrix

#include <stdio.h>

int main()
{
int Matrix[3][3] = {
{ 1, 2, 3 },
{ 4, 5, 6 },
{ 7, 8, 9 }
};

int i, j, n1, n2, temp;

printf("Matrix before row exchange:\n");
for (i = 0; i < 3; ++i) {
for (j = 0; j < 3; ++j)
printf(" %d", Matrix[i][j]);
printf("\n");
}

printf("Enter two row numbers to be exchanged:");
scanf("%d %d", &n1, &n2);

//Exchange rows
for (i = 0; i < 3; ++i) {
temp = Matrix[n1 - 1][i];

Matrix[n1 - 1][i] = Matrix[n2 - 1][i];
Matrix[n2 - 1][i] = temp;
}

printf("Matrix after row exchange:\n");
for (i = 0; i < 3; ++i) {
for (j = 0; j < 3; ++j)
printf(" %d", Matrix[i][j]);
printf("\n");
}

return 0;
}``````

Output:

```RUN 1:
Matrix before row exchange:
1 2 3
4 5 6
7 8 9
Enter two row numbers to be exchanged:1 3
Matrix after row exchange:
7 8 9
4 5 6
1 2 3

RUN 2:
Matrix before row exchange:
1 2 3
4 5 6
7 8 9
Enter two row numbers to be exchanged:1 2
Matrix after row exchange:
4 5 6
1 2 3
7 8 9

RUN 3:
Matrix before row exchange:
1 2 3
4 5 6
7 8 9
Enter two row numbers to be exchanged:2 3
Matrix after row exchange:
1 2 3
7 8 9
4 5 6
```

Explanation:

In the main() function, we created a 3X3 matrix matrix using the 2D array. Then we read row numbers to be exchanged. After that, we interchanged the rows and printed the updated matrix on the console screen.