Find the Transpose of a 2-D Matrix in C

This program finds the transpose of a given 2-D matrix (rows become columns and columns become rows).

C Program

#include <stdio.h>

int main() {
    int a[10][10], transpose[10][10];
    int m, n, i, j;

    printf("Enter number of rows (m) and columns (n): ");
    scanf("%d %d", &m, &n);

    printf("Enter elements of the matrix:\n");
    for (i = 0; i < m; i++)
        for (j = 0; j < n; j++)
            scanf("%d", &a[i][j]);

    for (i = 0; i < m; i++)
        for (j = 0; j < n; j++)
            transpose[j][i] = a[i][j];

    printf("Transpose of the matrix:\n");
    for (i = 0; i < n; i++) {
        for (j = 0; j < m; j++) {
            printf("%d ", transpose[i][j]);
        }
        printf("\n");
    }

    return 0;
}

Explanation

• The transpose of an m x n matrix is an n x m matrix where element [i][j] of the original becomes element [j][i] of the result.
• The assignment transpose[j][i] = a[i][j] does exactly this swap of row/column indices while copying.
• Since the transpose has swapped dimensions, the printing loops iterate up to n rows and m columns instead of the original m and n.

Sample Output

Enter number of rows (m) and columns (n): 2 3
Enter elements of the matrix:
1 2 3
4 5 6
Transpose of the matrix:
1 4
2 5
3 6