Data commit

Task/Mertens-function/ALGOL-W/mertens-function.alg

@@ -0,0 +1,33 @@
+begin % compute values of the Mertens function                      %
+    integer array M ( 1 :: 1000 );
+    integer k, zero, cross;
+    % Generate Mertens numbers                                      %
+    M( 1 ) := 1;
+    for n := 2 until 1000 do begin
+        M( n ) := 1;
+        for k := 2 until n do M( n ) := M( n ) - M( n div k )
+    end for_n ;
+    % Print table                                                   %
+    write( "The first 99 Mertens numbers are:" );
+    write( "   " );
+    k := 9;
+    for n := 1 until 99 do begin
+        writeon( i_w := 3, s_w := 0, M( n ) );
+        k := k - 1;
+        if k = 0 then begin
+            k := 10;
+            write()
+        end if_k_eq_0
+    end for_n ;
+    % Calculate zeroes and crossings                                %
+    zero  := 0;
+    cross := 0;
+    for n :=2 until 1000 do begin
+        if M( n ) = 0 then begin
+            zero := zero + 1;
+            if M( n - 1 ) not = 0 then cross := cross + 1
+        end if_M_n_eq_0
+    end for_n ;
+    write( i_w := 2, s_w := 0, "M(N) is zero ", zero, " times." );
+    write( i_w := 2, s_w := 0, "M(N) crosses zero ", cross, " times." )
+end.