Lets take a matrix of 4*4 i.e. int matrix [4][4];
11 12 13 14
21 22 23 24
31 32 33 34
41 42 43 44
So diagonal element of this matrix is 11, 22, 33 and 44 now see the program below
for (i = 0; i < N; i++)
for (j = 0; j < N; j++)
if (i == j)
printf(“Diagonal element is : %d\n”,matrix[i][j]);
Also we can optimize above program like given below:
for (i=0, j=0; i < N; i++, j++)
printf(“Diagonal element is : %d\n”,matrix[i][j]);
Also interviewer can ask print diagonal element of an N*N matrix in reverse order.
for (i=N-1, j=N-1; i >= 0; i–, j–)
printf(“Diagonal element in reverse order is : %d\n”,matrix[i][j]);