uses crt;

var s:string;

i,d,dem:integer;

begin

clrscr;

write('Nhap xau S:'); readln(s);

d:=length(s);

writeln('Cac ki tu so co trong xau S:'); 

dem:=0;

for i:=1 to d do 

  if s[i] in ['0'..'9'] then

begin

write(s[i]:4);

inc(dem);

end;

writeln;

writeln('So ki tu chu so co trong xau S: ',dem);

for i:=1 to d do 

  if s[i] in ['0'..'9'] then s[i]:='A'

writeln('Xau sau khi doi la: ',s);

readln;

end.

Program HOC24;

var s: string;

i: byte;

begin

write('Nhap xau :'); readln(s);

for i:=1 to length(s) do if s[i]<>'a' then write(s[i]);

readln

end.

uses crt;

var st:string;

i,d:integer;

begin

clrscr;

write('Nhap xau:'); readln(st);

d:=length(st);

for i:=1 to d do 

 if st[i]='a' then delete(st,i,1);

writeln(st);

readln;

end.

uses crt;

var st:string;

begin

clrscr;

write('Nhap xau:'); readln(st);

writeln(length(st));

readln;

end.

Chương trình:

program bai_10_chuong_4;

uses crt;

var

s: string[100];

i, dem: integer;

Begin

clrscr;

write('Nhap xau vao:'); readln(s); dem:= 0;

for i:= 1 to length(s) do

if ('0'<=s[i]) and(s[i]<=’9') then dem:=dem+l;

Writeln('Trong xau s co '»dem,' chu so thap phan');

readln;

End.

uses crt;

var s:string;

i,d,dem:integer;

begin

clrscr;

write('Nhap xau S:'); readln(s);

d:=length(s);

dem:=0;

for i:=1 to d do 

  if st[i]=#32 then inc(dem);

writeln(dem);

readln;

end.

program bai1;
uses crt;
var i:integer;
s,s1:string;
begin
  clrscr;
  write('nhap S:');readln(s);
  while pos('C',s)<>0 do
  begin
    insert('LOP11A',s,pos('C',s));
    delete(s,pos('C',s),1);
  end;
  writeln('xau sau khi bien doi la: ',s);
  writeln('do dai cua xau tren la: ',length(s));
  write('nhap s1:');readln(s1);
  if s1[1]=s[1] then writeln('ki tu dau cua hai xau trung nhau')
  else writeln('ki tu dau cua hai xau khong trung nhau');
  readln;
end.

program st;

ues crt;

var s:string;i:longint;

begin

 clrscr;

   write('nhap do dai cua xau');readln(s);

    if (s>=25)then

         begin 

             write('nhap lai s nho hon 25');readln(s);

          end;

   for i:=1 to length(s) do writeln(s[i]);

readln;

end. 

chj check ib em ạ

#include <bits/stdc++.h>

using namespace std;

string s;

int d,i,dem;

int main()

{

cin>>s;

d=s.length();

dem=0;

for (i=0; i<=d-1; i++)

if (s[i]=='a') dem++;

cout<<dem;

return 0;

}

s = input("Nhập xâu S: ")

k = input("Nhập kí tự k: ")

count = 0

for c in s:

     if c == k:

          count += 1

print("Số lần xuất hiện của kí tự k trong xâu S là:", count)