: , : ! , , . . , , , . . , :
D :
((Xc-Xa)(Xb-Xa) - (Yc-Ya)(Yb-Ya))((Xd-Xa)(Xb-Xa) - (Yd-Ya)(Yb-Ya))<0
A B CD:
((Xa-Xc)(Xd-Xc) - (Ya-Yc)(Yd-Yc))((Xb-Xc)(Xd-Xc) - (Yb-Yc)(Yd-Yb))<0
, , , , (. ). :
program line2;
var x1,x2,x3,x4,y1,y2,y3,y4: integer;
begin
writeln(' :');
write(' = ');readln(x1);
write('Ya = ');readln(y1);
writeln(' B:');
write('b = ');readln(x2);
write('Yb = ');readln(y2);
writeln(' C:');
write('c = ');readln(x3);
write('Yc = ');readln(y3);
writeln(' D:');
write('d = ');readln(x4);
write('Yd = ');readln(y4);
if (((x3-x1)*(x2-x1)-(y3-y1)*(y2-y1))*((x4-x1)*(x2-x1)-(y4-y1)*(y2-y1))<=0) and
(((x1-x3)*(x4-x3)-(y1-y3)*(y4-y3))*((x2-x3)*(x4-x3)-(y2-y3)*(y4-y3))<=0)
then writeln('.')
else writeln(' ');
readln
end.
Case
. , .
57.57. .
: :
program ocenka1;
var o: integer;
begin
write(i i: );
readln(o);
if o = 5 then writeln(! i .)
else if o = 4 then writeln(! !)
else if o = 3 then writeln(i !)
else if o = 2 then writeln( .)
else writeln(, i .);
readln
end.
. , , else if . . :
, :
1 1;
2 2;
...
n n.
, , , :
|
|
...
case o of
{ }
<01>: <1>; { }
<02>: <2>; { }
<03>: <3>; { }
<04>: <4>; { }
end;
{ }
...
, , , begin... end. , case , , else. , else .
, , , case end, .
.
program ocenka2;
var o: integer;
begin
write(i i: );
readln(o);
case o of
5: writeln(! i .);
4: writeln(! !);
3: writeln(i !);
2: writeln( .)
else writeln(, i .);
end; { case }
readln
end.
.
ֳ , 䳿 . .