Bai 5:

uses crt;
var a:array[1..10000] of longint;
    i,dem,dem1:longint;
    s:string;
begin
clrscr;
readln(s);
for i:=1 to length(s) do
begin
if s[i] in ['a'..'z'] then
dem:=dem+1;
if s[i] in ['0'..'9'] then
dem1:=dem1+1;
if s[i] in ['A'..'Z'] then
dem1:=dem1+1;
end;
write(dem,' ',dem1);
readln;
end.

Bai 6:

uses crt;
var s:string;
    i,dem,j:longint;
    t:char;
begin
clrscr;
readln(s);
dem:=1;
for i:=1 to length(s) do
begin
 for j:=i+1 to length(s) do
 begin
  if s[i]>s[j] then
  begin
   t:=s[i];
   s[i]:=s[j];
   s[j]:=t;
  end;
 end;
end;
for i:=1 to length(s) do
begin
 if s[i]=s[i+1] then
  dem:=dem+1
 else
 begin
 writeln(s[i],' : ',dem);
 dem:=1;
 end;
end;
readln;
end.

bài 5:

uses crt;
var s,s2,s3:string;
i,d1,d2:integer;
begin
clrscr;
write('nhap chuoi:');readln(s);
for i:=1 to length(s) do
 if s[i] in ['a'..'z'] then d1:=d1+1
 else if s[i] in['0'..'9'] then d2:=d2+1;
writeln('xau co ',d1,' ky tu chu va ',d2,' ky tu so');
readln;
end.

bài 6:

uses crt;
var s:string;
i,d,j:integer;
tam:char;
begin
clrscr;
write('nhap chuoi:');readln(s);
for i:=1 to length(s)-1 do
for j:=i+1 to length(s) do
 if s[i]<s[j] then
 begin
  tam:=s[i];
  s[i]:=s[j];
  s[j]:=tam;
 end;
i:=1;
upcase(s);
while i<=length(s) do
begin
d:=1;
if s[i]<>' ' then
begin
 write(s[i],':');
 while upcase(s[i])=upcase(s[i+1]) do begin i:=i+1; d:=d+1;end;
 writeln(d);
end;
 i:=i+1;
end;
readln;
end.