Damm algorithm: Difference between revisions

=={{header|Cowgol}}==

<lang cowgol>include "cowgol.coh";

# Damm test on number given as ASCII string

# Returns check digit

sub damm(num: [uint8]): (chk: uint8) is

var table: uint8[] := {

0,3,1,7,5,9,8,6,4,2,

7,0,9,2,1,5,4,8,6,3,

4,2,0,6,8,7,1,3,5,9,

1,7,5,0,9,8,3,4,2,6,

6,1,2,3,0,4,5,9,7,8,

3,6,7,4,2,0,9,5,8,1,

5,8,6,9,7,2,0,1,3,4,

8,9,4,5,3,6,2,0,1,7,

9,4,3,8,6,1,7,2,0,5,

2,5,8,1,4,3,6,7,9,0

};

chk := 0;

while [num] != 0 loop

chk := table[(chk<<1) + (chk<<3) + ([num] - '0')];

num := @next num;

end loop;

end sub;

# Test and print

sub test(num: [uint8]) is

print(num);

print(":");

if damm(num) == 0 then

print("Pass\n");

else

print("Fail\n");

end if;

end sub;

test("5724");

test("5727");

test("112946");

test("112949");</lang>

{{out}}

<pre>5724:Pass

5727:Fail

112946:Pass

112949:Fail</pre>