s = input("Nhập xâu s: ")
x = input("Nhập xâu x: ")
count = 0

for i in range(len(s) - len(x) + 1):
    if s[i:i+len(x)] == x:
        count += 1

if count == 0:
    print("Không xuất hiện")
else:
    print("Số lần xuất hiện của x trong s là:", count)

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 st:string;

i,d,dem:integer;

begin

clrscr;

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

d:=length(st);

writeln('Xau vua nhap la: ',st);

dem:=0;

for i:=1 to d do 

  if st[i] in ['0'..'9'] then inc(dem);

writeln(dem);

readln;

end.

uses crt;

var st,s:string;

    i,d,dem,kt,j,dem1:integer;

begin

clrscr;

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

writeln('Xau vua nhap la: ',s);

d:=length(s);

for i:=1 to d do

  if s[i]=#32 then delete(s,i,1);

dem:=1;

st[1]:=s[1];

for i:=1 to d do

  begin

     kt:=0;

     for j:=1 to dem do

       if s[i]=st[j] then kt:=1;

     if kt=0 then

        begin

           inc(dem);

           st[dem]:=s[i];

        end;

  end;

for i:=1 to dem do

  begin

     dem1:=0;

     for j:=1 to d do

       if st[i]=s[j] then inc(dem1);

     writeln(st[i],' xuat hien ',dem1,' lan');

  end;

readln;

end.

Program HOC24;

var s: string;

i,d: byte;

begin

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

d:=0;

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

write('Xau ',s,' co ',d,' ki tu cach');

readln

end.

uses crt;

var s:string;

i,d,dem:integer;

begin

clrscr;

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

d:=length(s);

dem:=0;

for i:=1 to d do 

  if s[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.

uses crt;

var st:string;

i,d,dem:integer;

ch:char;

begin

clrscr;

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

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

d:=length(st);

dem:=0;

while pos(ch,st)>0 do 

  begin

inc(dem);

delete(st,pos(ch,st),1);

end;

writeln(dem);

readln;

end.