You can use the following code to print the tabula recta.
#include <stdio.h>
void
print_tabula_recta()
{
int i, j, k, l;
/* prepare the top part of the table */
printf(" | ");
for (i = 65; i <= 90; i++)
printf("%c ", i);
putchar('\n');
/* outer rim */
for (i = 1; i <= 109; i++)
printf("-");
putchar('\n');
/* print the actual table to stdout */
for (i = 0; i <= 25; i++) {
printf(" %c | ", i + 65);
for (j = 65; j <= 90; j++) {
k = i;
l = j;
l = l + k;
if(l <= 90)
printf("%c ", l);
else {
l = l - (90 - 65 + 1);
printf("%c ", l);
}
}
putchar('\n');
}
}
int
main()
{
print_tabula_recta();
return(0);
}
Compile the code as follows:
gcc -o tabula_recta tabula_recta.cAnd run it with:
tabula_rectaTo generate the following output:
| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
-------------------------------------------------------------------------------------------------------------
A | A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
B | B C D E F G H I J K L M N O P Q R S T U V W X Y Z A
C | C D E F G H I J K L M N O P Q R S T U V W X Y Z A B
D | D E F G H I J K L M N O P Q R S T U V W X Y Z A B C
E | E F G H I J K L M N O P Q R S T U V W X Y Z A B C D
F | F G H I J K L M N O P Q R S T U V W X Y Z A B C D E
G | G H I J K L M N O P Q R S T U V W X Y Z A B C D E F
H | H I J K L M N O P Q R S T U V W X Y Z A B C D E F G
I | I J K L M N O P Q R S T U V W X Y Z A B C D E F G H
J | J K L M N O P Q R S T U V W X Y Z A B C D E F G H I
K | K L M N O P Q R S T U V W X Y Z A B C D E F G H I J
L | L M N O P Q R S T U V W X Y Z A B C D E F G H I J K
M | M N O P Q R S T U V W X Y Z A B C D E F G H I J K L
N | N O P Q R S T U V W X Y Z A B C D E F G H I J K L M
O | O P Q R S T U V W X Y Z A B C D E F G H I J K L M N
P | P Q R S T U V W X Y Z A B C D E F G H I J K L M N O
Q | Q R S T U V W X Y Z A B C D E F G H I J K L M N O P
R | R S T U V W X Y Z A B C D E F G H I J K L M N O P Q
S | S T U V W X Y Z A B C D E F G H I J K L M N O P Q R
T | T U V W X Y Z A B C D E F G H I J K L M N O P Q R S
U | U V W X Y Z A B C D E F G H I J K L M N O P Q R S T
V | V W X Y Z A B C D E F G H I J K L M N O P Q R S T U
W | W X Y Z A B C D E F G H I J K L M N O P Q R S T U V
X | X Y Z A B C D E F G H I J K L M N O P Q R S T U V W
Y | Y Z A B C D E F G H I J K L M N O P Q R S T U V W X
Z | Z A B C D E F G H I J K L M N O P Q R S T U V W X Y
Which is the tabula recta.
Sources: Tabula recta