Data commit

Task/Hamming-numbers/ALGOL-W/hamming-numbers.alg

@@ -0,0 +1,41 @@
+begin
+    % returns the minimum of a and b                    %
+    integer procedure min ( integer value a, b ) ; if a < b then a else b;
+    % find and print Hamming Numbers                        %
+    % Algol W only supports 32-bit integers so we just find %
+    % the 1691 32-bit Hamming Numbers                       %
+    integer MAX_HAMMING;
+    MAX_HAMMING := 1691;
+    begin
+        integer array H( 1 :: MAX_HAMMING );
+        integer p2, p3, p5, last2, last3, last5;
+        H( 1 ) := 1;
+        last2  := last3 := last5 := 1;
+        p2     := 2;
+        p3     := 3;
+        p5     := 5;
+        for hPos := 2 until MAX_HAMMING do begin
+            integer m;
+            % the next Hamming number is the lowest of the next multiple of 2, 3, and 5 %
+            m := min( min( p2, p3 ), p5 );
+            H( hPos ) := m;
+            if m = p2 then begin
+                last2 := last2 + 1;
+                p2    := 2 * H( last2 )
+            end if_used_power_of_2 ;
+            if m = p3 then begin
+                last3 := last3 + 1;
+                p3    := 3 * H( last3 )
+            end if_used_power_of_3 ;
+            if m = p5 then begin
+                last5 := last5 + 1;
+                p5    := 5 * H( last5 )
+            end if_used_power_of_5 ;
+        end for_hPos ;
+        i_w := 1;
+        s_w := 1;
+        write( H( 1 ) );
+        for i := 2 until 20 do writeon( H( i ) );
+        write( H( MAX_HAMMING ) )
+    end
+end.