- Sử dụng For .. to .. do

uses crt;

var i, N, T : integer;

begin

clrscr;

write('Nhap so N = '); readln(N);

T := 1;

for i := 1 to N do T := T * i;

write('Tich = ', T );

readln

end.

- Sử dụng While .. do

uses crt;

var i, N, T : integer;

begin

clrscr;

write('Nhap so N = '); readln(N);

T := 1; i := 1;

while i <= N do

begin T := T * i;

i := i + 1; end;

write('Tich = ', T );

readln

end.

- Sử dụng For...to..do

Program timtich;

Uses crt;

Var i,tich,N:longint;

Begin

Write('Nhap so N: '); Readln(N);

tich:=1;

For i:=1 to N do tich:=tich*i;

Writeln('Tich ',N,' so tu nhien dau tien la: ',tich);

Readln;

End.

- Sử dụng While...do...

Program timtich;

Uses crt;

Var i,tich,N:longint;

Begin

Write('Nhap so N: '); Readln(N);

tich:=1;

While i<=N do begin tich:=tich*i; i:=i+1; end;

Writeln('Tich ',N,' so tu nhien dau tien la: ',tich);

Readln;

End.