Data commit

Task/Digital-root/ALGOL-W/digital-root.alg

@@ -0,0 +1,63 @@
+begin
+
+    % calculates the digital root and persistence of an integer in base 10   %
+    % in order to allow for numbers larger than 2^31, the number is passed   %
+    % as the lower and upper digits e.g. 393900588225 can be processed by    %
+    % specifying upper = 393900, lower = 58825                               %
+    procedure findDigitalRoot( integer value  upper, lower
+                             ; integer result digitalRoot, persistence
+                             ) ;
+    begin
+
+        integer procedure sumDigits( integer value n ) ;
+        begin
+            integer digits, sum;
+
+            digits := abs n;
+            sum    := 0;
+
+            while digits > 0
+            do begin
+                sum    := sum + ( digits rem 10 );
+                digits := digits div 10
+            end % while digits > 0 % ;
+
+            % result: % sum
+        end sumDigits;
+
+        digitalRoot := sumDigits( upper ) + sumDigits( lower );
+        persistence := 1;
+
+        while digitalRoot > 9
+        do begin
+            persistence := persistence + 1;
+            digitalRoot := sumDigits( digitalRoot );
+        end % while digitalRoot > 9 % ;
+
+    end findDigitalRoot ;
+
+    % calculates and prints the digital root and persistence                 %
+    procedure printDigitalRootAndPersistence( integer value upper, lower ) ;
+    begin
+        integer digitalRoot, persistence;
+        findDigitalRoot( upper, lower, digitalRoot, persistence );
+        write( s_w := 0  % set field saeparator width for this statement %
+             , i_w := 8  % set integer field width for this statement    %
+             , upper
+             , ", "
+             , lower
+             , i_w := 2  % change integer field width %
+             , ": digital root: "
+             , digitalRoot
+             , ", persistence: "
+             , persistence
+             )
+    end printDigitalRootAndPersistence ;
+
+    % test the digital root and persistence procedures %
+    printDigitalRootAndPersistence(      0, 627615 );
+    printDigitalRootAndPersistence(      0,  39390 );
+    printDigitalRootAndPersistence(      0, 588225 );
+    printDigitalRootAndPersistence( 393900, 588225 )
+
+end.