Data update

Task/Jacobi-symbol/PascalABC.NET/jacobi-symbol.pas

@@ -0,0 +1,34 @@
+function jacobi(n, k: integer): integer;
+begin
+  assert((k > 0) and (k mod 2 = 1));
+  n := n mod k;
+  result := 1;
+  while n <> 0 do
+  begin
+    while n mod 2 = 0 do
+    begin
+      n := n shr 1;
+      if (k and 7) in [3, 5] then
+        result := -result;
+    end;
+    swap(n, k);
+    if ((n and 3) = 3) and ((k and 3) = 3) then
+      result := -result;
+    n := n mod k;
+  end;
+  if k <> 1 then result := 0;
+end;
+
+begin
+  write('n/k|');
+  for var n := 1 to 20 do write(n:3);
+  writeln(#10, '—' * 64);
+
+  for var k := 1 to 21 step 2 do
+  begin
+    write(k:2, ' |');
+    for var n := 1 to 20 do
+      write(jacobi(n, k):3);
+    writeln;
+  end;
+end.