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.

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.

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.

uses crt;

var st:string[50];

d,i:integer;

begin

clrscr;

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

d:=length(st);

for i:=1 to d do 

  if st[i] in ['a'..'z'] then write(st[i]:4);

readln;

end.

uses crt;

var st:string;

a:array[1..255]of string;

i,d,dem,kt,j,dem1:integer;

begin

clrscr;

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

d:=length(st);

a[1]:=st[1];

dem:=1;

for i:=1 to d do 

  begin

kt:=0;

for j:=1 to dem do 

  if st[i]=a[j] then kt:=1;

if kt=0 then 

begin

inc(dem);

a[dem]:=st[i];

end;

end;

for i:=1 to dem do 

  begin

dem1:=0;

for j:=1 to d do 

  if a[i]=st[j] then inc(dem1);

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

end;

readln;

end.

uses crt;

var a:string;

     c:char;

     i,dem:integer;

begin

    clrscr;

    readln(a);

    readln(c);

    dem:=0;

    for i:=1 to length(a) do

    if a[i]=c then dem:=dem+1;

    writeln(dem);

    readln;

end.

program stringManipulation;

var
  st1, st2: string;
  countN, i: integer;

begin
  write('Nhap vao xau ki tu st1: ');
  readln(st1);
  countN := 0;
  for i := 1 to length(st1) do
  begin
    if (st1[i] = 'N') or (st1[i] = 'n') then
    begin
      countN := countN + 1;
    end;
  end;
  writeln('So ky tu N va n trong xau st1 la: ', countN);
  st2 := ''
  for i := 1 to length(st1) do
  begin
    if (st1[i] >= 'A') and (st1[i] <= 'Z') then
    begin
      st2 := st2 + st1[i];
    end;
  end;
  writeln('Cac ky tu in hoa trong xau st1 la: ', st2);
  write('Xau st1 viet theo chieu nguoc lai la: ');
  for i := length(st1) downto 1 do
  begin
    write(st1[i]);
  end;
  readln;
end.

st1 = input("Nhập vào xâu kí tự: ")
count_n = 0
st2 = ""
for char in st1:
    if char == 'N' or char == 'n':
        count_n += 1
    if char.isupper():
        st2 += char

print("Số lần xuất hiện của kí tự 'N' và 'n' là:", count_n)
print("Xâu kí tự chỉ chứa kí tự in hoa là:", st2)
print("Xâu kí tự đảo ngược là:", st1[::-1])