câu 1 Uses Crt;

Var St:String;

dem: Array[‘A’..’Z’] Of Byte

; i:Byte;

ch:Char;

Begin Write(‘Nhap xau St: ‘);

Readln(St);

{Khởi tạo mảng} For ch:=’A’ To ‘Z’ Do dem[ch]:=0;

{Duyệt xâu} For i:=1 To Length(St) Do If Upcase(St[i]) IN [‘A’..’Z’] Then Inc(dem[Upcase(St[i])]);

{Liệt kê các ký tự ra màn hình} For ch:=’A’ To ‘Z’ Do If dem[ch]>0 Then Writeln(ch,’ : ’,dem[ch]);

Readln;

Hehe,con sâu

Var st:string;

i,dem:integer;

Begin

Write('Nhap xau ky tu ');readln(st);

For i:=1 to length(st) do

If st[i] = 'a' then dem:=dem+1;

Write('So ky tu a co trong xau la ',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:integer;

Begin

Clrscr;

Write('nhap xau:'); readln(st);

D:=length(st);

While st[d]=#32 do

Begin

Delete(st,d,1);

D:=length(st);

End;

For i:=1 to d do

If (st[i]=#32) and (st[i+1]=#32) then delete(st,i,1);

Writeln(st);

Readln;

End.

Uses crt;

Var st:string;

I,d:integer;

Begin

Clrscr;

Write('nhap xau:'); readln(st);

D:=length(st);

While st[d]=#32 do

  Begin

Delete(st,d,1);

D:=length(st);

End;

For i:=1 to d do

  If (st[i]=#32) and (st[i+1]=#32) then delete(st,i,1);

Writeln(st);

Readln;

End.

Bài 1:

uses crt;

var S:String;

vt:integer;

begin

clrscr;

Write(‘Nhap 1 xau:’); Readln(S);

While pos(‘nang’,s)>0 do

Begin

Vt:= pos(‘nang’,s);

Delete(s,vt,4);

Insert(‘mua’,s ,vt);

End;

Writeln(‘Xau sau khi thay the ’,s);

Readln;

End.

Bài 2: 

uses crt;

var st:string;

d,i,kt:integer;

begin

clrscr;

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

d:=length(st);

kt:=0;

for i:=1 to d do 

  if st[i]<>st[d-i+1] then kt:=1;

if kt=0 then writeln(st,' la xau doi xung')

else writeln(st,' khong la xau doi xung');

readln;

end.

var a,b:string;

begin

 write('a = '); readln(a);

write('b = '); readln(b);

if a[2] = b[length(b)-1] then write('Có trùng') else write('Không trùng');

readln

end.

uses crt;

var st:string;

i,d:integer;

begin

clrscr;

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

d:=length(st);

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

for i:=1 to d do 

  if st[i]=#32 then delete(st,i,1);

writeln('Xau moi la: ',st);

readln;

end.