st = str(input())

Program HOC24;

var i,d: byte;

s: string;

begin

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

d:=0;

for i:=1 to length(s) do if s[i] in ['0'..'9'] then d:=d+1;

write('Co ',d,' ki tu so trong xau');

readln

end.

Giải giúp mk vói🥰

uses crt;

var st:string;

n,vt,d,i:integer;

begin

clrscr;

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

d:=length(st);

write('Nhap vi tri can xoa:'); readln(vt);

write('Nhap so ki tu can xoa:'); readln(n);

delete(st,vt,n);

writeln('Xau sau khi xoa la: ',st);

readln;

end.

Program HOC24;

var s: string;

x: char;

d: byte;

begin

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

write('Nhap ki tu: '); readln(x);

d:=0;

for i:=1 to length(s) do if s[i]=x then d:=d+1;

if d=0 then write('Ki tu do khong xuat hien trong xau') else write('Ki tu do xuat hien trong xau');

readln

end.

uses crt;

var st:string;

d,i:integer;

begin

clrscr;

readln(st);

d:=length(st);

for i:=1 to d do 

  if not (st[i] in ['0'..'9']) then write(st[i]);

readln;

end.

uses crt;

var st:string;

begin

clrscr;

readln(st);

delete(st,3,5);

writeln(st);

readln;

end.

program TongN;

var

     n, i, tong: integer;

begin

     tong := 0;

     writeln('Nhap so nguyen duong N: ');

     readln(n);

     i := 0;

     while i < n do

     begin

          i := i + 1;

          tong := tong + i;

     end;

     writeln('Tong cac so tu 1 den ', n, ' la ', tong);

     readln;

end.

xau = input("Nhập vào một xâu bất kì: ")

xau_moi = xau.replace("choi", "hoc")

print("Xâu mới sau khi thay thế là:", xau_moi)

Program HOC24;

var s: string;

d: byte;

begin

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

while pos('choi',s)<>0 do

begin

d:=pos('choi',s);

delete(s,d,4);

insert('hoc',s,d);

end;

write('Xau sau khi thay la: ',s);

readln

end.