procedure TForm1.btn1Click(Sender: TObject); var a, b, c: Integer; begin mmo1.Clear ; for a := 97 to 120 do begin for b := (a + 1) to 121 do begin for c := (b + 1) to 122 do begin mmo1.Lines.Add(chr(a) + '-' + chr(b) + '-' + chr(c)); end; end; end; end;
则有a-b-c,a-b-d,a-b-e,a-c-d,a-c-e,a-d-e,b-c-d,b-c-e,b-d-e,c-d-e共10,公式为5*4*3/6 = 10
a-b-c, a-b-d, a-b-e, a-c-d, a-c-e,
a-d-e, b-c-d, b-c-e, b-d-e, c-d-e
....
var
a, b, c: Integer;
begin
mmo1.Clear ;
for a := 97 to 120 do
begin
for b := (a + 1) to 121 do
begin
for c := (b + 1) to 122 do
begin
mmo1.Lines.Add(chr(a) + '-' + chr(b) + '-' + chr(c));
end;
end;
end;
end;