langs a-z

Task/Knuth-shuffle/Pascal/knuth-shuffle.pascal

@@ -0,0 +1,33 @@
+program Knuth;
+
+const
+  max = 10;
+type
+  list = array [1..max] of integer;
+
+procedure shuffle(var a: list);
+var
+  i,k,tmp: integer;
+begin
+  randomize;
+  for i := max downto 2 do begin
+     k := random(i) + 1;
+     if (a[i] <> a[k]) then begin
+       tmp := a[i]; a[i] := a[k]; a[k] := tmp
+     end
+  end
+end;
+
+{ Test and display }
+var
+ a: list;
+ i: integer;
+
+begin
+  for i := 1 to max do
+    a[i] := i;
+  shuffle(a);
+  for i := 1 to max do
+    write(a[i], ' ');
+  writeln
+end.