Data commit

Task/Tau-function/ALGOL-W/tau-function.alg

@@ -0,0 +1,36 @@
+begin % find the count of the divisors of the first 100 positive integers   %
+    % calculates the number of divisors of v                                %
+    integer procedure divisor_count( integer value v ) ; begin
+        integer total, n, p;
+        total := 1; n := v;
+        % Deal with powers of 2 first %
+        while not odd( n ) do begin
+            total := total + 1;
+            n     := n div 2
+        end while_not_odd_n ;
+        % Odd prime factors up to the square root %
+        p := 3;
+        while ( p * p ) <= n do begin
+            integer count;
+            count := 1;
+            while n rem p = 0 do begin
+                count := count + 1;
+                n     := n div p
+            end while_n_rem_p_eq_0 ;
+            p     := p + 2;
+            total := total * count
+        end while_p_x_p_le_n ;
+        % If n > 1 then it is prime %
+        if n > 1 then total := total * 2;
+        total
+    end divisor_count ;
+    begin
+        integer limit;
+        limit := 100;
+        write( i_w := 1, s_w := 0, "Count of divisors for the first ", limit, " positive integers:" );
+        for n := 1 until limit do begin
+            if n rem 20 = 1 then write();
+            writeon( i_w := 3, s_w := 1, divisor_count( n ) )
+        end for_n
+    end
+end.