RosettaCodeData/Task/Digital-root-Multiplicative-digital-root/ALGOL-68/digital-root-multiplicative-digital-root.alg
2015-02-20 09:02:09 -05:00

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# Multiplicative Digital Roots #
# structure to hold the results of calculating the digital root & persistence #
MODE DR = STRUCT( INT root, INT persistence );
# calculate the multiplicative digital root and persistence of a number #
PROC md root = ( INT number )DR:
BEGIN
# calculate the product of the digits of a number #
PROC digit product = ( INT number )INT:
BEGIN
INT result := 1;
INT rest := number;
WHILE
result TIMESAB ( rest MOD 10 );
rest OVERAB 10;
rest > 0
DO
SKIP
OD;
result
END; # digit product #
INT mp := 0;
INT mdr := ABS number;
WHILE mdr > 9
DO
mp +:= 1;
mdr := digit product( mdr )
OD;
( mdr, mp )
END; # md root #
# prints a number and its MDR and MP #
PROC print md root = ( INT number )VOID:
BEGIN
DR mdr = md root( number );
print( ( whole( number, -6 )
, ": MDR: ", whole( root OF mdr, 0 )
, ", MP: ", whole( persistence OF mdr, -2 )
, newline
)
)
END; # print md root #
# prints the first few numbers with each possible Multiplicative Digital #
# Root. The number of values to print is specified as a parameter #
PROC tabulate mdr = ( INT number of values )VOID:
BEGIN
[ 0 : 9, 1 : number of values ]INT mdr values;
[ 0 : 9 ]INT mdr counts;
mdr counts[ AT 1 ] := ( 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 );
# find the first few numbers with each possible mdr #
INT values found := 0;
INT required values := 10 * number of values;
FOR value FROM 0 WHILE values found < required values
DO
DR mdr = md root( value );
IF mdr counts[ root OF mdr ] < number of values
THEN
# need more values with this multiplicative digital root #
values found +:= 1;
mdr counts[ root OF mdr ] +:= 1;
mdr values[ root OF mdr, mdr counts[ root OF mdr ] ] := value
FI
OD;
# print the values #
print( ( "MDR: [n0..n" + whole( number of values - 1, 0 ) + "]", newline ) );
print( ( "=== ========", newline ) );
FOR mdr pos FROM 1 LWB mdr values TO 1 UPB mdr values
DO
STRING separator := ": [";
print( ( whole( mdr pos, -3 ) ) );
FOR val pos FROM 2 LWB mdr values TO 2 UPB mdr values
DO
print( ( separator + whole( mdr values[ mdr pos, val pos ], 0 ) ) );
separator := ", "
OD;
print( ( "]", newline ) )
OD
END; # tabulate mdr #
main:(
print md root( 123321 );
print md root( 7739 );
print md root( 893 );
print md root( 899998 );
tabulate mdr( 5 )
)