For a better understanding, we always recommend you to learn the basic topics of C programming listed below:

We want to interchange the Rows and Columns of a given Matrix; as we discussed, the Matrix is a set of elements in a Row and Column format. So what we are doing is that we need to interchange the Row and Column. For example, a **Matrix [123]** and Column interchange **2** and** 3 **means the resulting Matrix will be **[132] **like that in Row also.

In this C program, after accepting the user Matrix, we are getting the Columns and Rows that need to be interchanged. First, we interchange the Row; after the Row interchange, we interchange the Columns.

The logic of this C program is, first declare two Matrix '**m1**' and '**m2**'.Then read the Order of the Matrix into '**m**' and '**n**'. Then read the Matrix from the user and save it into '**m1 **and **m2**. Read the number of Rows to be exchanged into the variables '**a**' and '**b**'. Then interchange the Rows using `for loop`

and keep it in the Matrix **m1**. Read the number of columns to be exchanged into the variable '**p**' and '**q**'. Display the given Matrix as the elements in **m2**. Then interchange the Columns in '**m2**' by using `for loop`

and saving them in **m2**. Finally, display the Matrix after Row interchange as **m1 **and the Matrix after Column interchange as **m2**.

**STEP 1:** Include the header files to use the built-in functions in the C program.

**STEP 2:** Declare the matrix variables **m1[ ][ ],m2[ ][ ]** as integer type.

**STEP 3:** Declare the integer variables** i,j,m,n,a,b,c,p,q,r**.

**STEP 4:** Read the Order of the Matrix into **m **and **n**.

**STEP 5**: Use a nested `for loop`

with conditions **i and j **for reading elements of matrix

**STEP 6: **Read the number of rows to be exchanged into the variables

**STEP 7**: By using `for loop`

with the condition **i,** do step8

**STEP 8**: Swap the elements of rows as follows

**c = m1[a-1][i]****m1[a-1][i] = m1[b-1][i]****m1[b-1][i] = c.**

**STEP 9**: Read the number of columns to be exchanged into the variables **p** and **q**.

**STEP 10**: By using `for loop`

display the given Matrix stored in **m2**, because **m1** has the row interchanged matrix.

**STEP 11**: Use a for loop with the condition **i**, do step12

**STEP 12**: Swap the elements of columns as follows

**r = m2[i][p-1]****m2[i][p-1] = m2[i][q-1]****m2[i][q-1] = r.**

**STEP 13**: Display the Matrix **m1 **after interchanging the two Rows.

**STEP 14**: Display the Matrix **m2 **after interchanging the two Columns.

` ````
#include <stdio.h>
void main() {
static int m1[10][10], m2[10][10];
int i, j, m, n, a, b, c, p, q, r;
printf("Enter the order of the matrix\n");
scanf("%d * %d", & m, & n);
printf("Enter the coefficients of the matrix\n");
for (i = 0; i < m; ++i) {
for (j = 0; j < n; ++j) {
scanf("%d", & m1[i][j]);
m2[i][j] = m1[i][j];
}
}
printf("Enter the numbers of two rows to be exchanged \n");
scanf("%d %d", & a, & b);
for (i = 0; i < m; ++i) {
c = m1[a - 1][i]; /* first row has index is 0 */
m1[a - 1][i] = m1[b - 1][i];
m1[b - 1][i] = c;
}
printf("Enter the numbers of two columns to be exchanged\n");
scanf("%d %d", & p, & q);
printf("The given matrix is \n");
for (i = 0; i < m; ++i) {
for (j = 0; j < n; ++j)
printf(" %d", m2[i][j]);
printf("\n");
}
for (i = 0; i < n; ++i) {
r = m2[i][p - 1]; /* first column index is 0 */
m2[i][p - 1] = m2[i][q - 1];
m2[i][q - 1] = r;
}
printf("The matrix after interchanging the two rows(in the original matrix)\n");
for (i = 0; i < m; ++i) {
for (j = 0; j < n; ++j) {
printf(" %d", m1[i][j]);
}
printf("\n");
}
printf("The matrix after interchanging the two columns(in the original matrix)\n");
for (i = 0; i < m; ++i) {
for (j = 0; j < n; ++j)
printf(" %d", m2[i][j]);
printf("\n");
}
}
```

Enter the order of the matrix 3*3 Enter the co-efficient of the matrix 1 2 4 5 7 9 3 0 6 Enter the numbers of two rows to be exchanged 1 2 Enter the numbers of two columns to be exchanged 2 3 The given matrix is 1 2 4 5 7 9 3 0 6 The matrix after interchanging the two rows (in the original matrix) 5 7 9 1 2 4 3 0 6 The matrix after interchanging the two columns(in the original matrix) 1 4 2 5 9 7 3 6 0