a)
program xau;
uses crt;
var s:String;
i, d: Byte;
th: set of char;
begin
clrscr;
th:=['1','2','3','4','5','6','7','8','9','0'];
write('nhap xau: '); readln(s);
d:=0;
for i:=1 to length(s) do if s[i] in th then
inc(d);
write('Trong xau co ', d, ' chu so');
readln;
end.
b)
program xau;
uses crt;
var s:String;
i: Byte;
begin
clrscr;
write('nhap xau: '); readln(s);
i:=1;
While i<length(s) do
Begin
If (s[i]=' ') and (s[i+1]=' ') then
Begin
Delete(s, i, 1); dec(i);
End;
Inc(i);
End;
While s[1]=' ' do delete(s, 1, 1);
While s[length(s)]=' ' do delete(s, length(s), 1);
Writeln(s);
readln;
end.
