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;

End.

câu 2

var s:string;
    i,dem:integer;
begin
   write('Nhap xau: '); readln(s);
   for i:=1 to length(s) do
   S[i]:=upcase(S[i]);
   for i:=1 to length(s) do
   if copy(s,i,3)='a' then inc(dem);
   writeln('So tu "a" xuat hien trong xau la: ',dem);
   readln
end.

câu 3

var s:string;
begin
clrscr;
write('Nhap chuoi: ');readln(s);
While (s[1]=' ') do Delete(s,1,1);
While (s[Length(s)]=' ') do Delete(s,Length(s),1);
While (Pos(' ',s)<>0) do Delete(s,Pos(' ',s),1);
writeln('Xau sau khi xoa ki tu rong.',s);
readln;
end.

câu 5

var s1,s2:string;
 i:integer;
begin
 clrscr;
 write('Nhap xau: '); readln(s1);
 s2:='';
 for i:=1 to length(s1) do
 if ('a'<=s1[i]) and ('z'>=s1[i]) then s2:=s2+s1[i];
 writeln;
 write(s2);
 readln
end.

Câu 1:

Program NN;
Uses crt;
Var St: String;
    k: char;
    i,d: longint;
Begin
        Clrscr;
        Write('Nhap St: '); Readln(St);
        Write('Nhap ki tu: '); Readln(k);
        d:=0;
        For i:=1 to length(St) do
                If St[i]=k then inc(d);
        Write(d);
        Readln
End.

Câu 2:

Program NN;
Uses crt;
Var St: String;
    i,d: longint;
Begin
        Clrscr;
        Write('Nhap St: '); Readln(St);
        d:=0;
        For i:=1 to length(St) do
                If St[i]='a' then inc(d);
        Write(d);
        Readln
End.

Câu 3:

Program Xau;
Uses crt;
Var St: String;
    i: longint;

Begin
        Clrscr;
        Write('Nhap xau: '); Readln(St);
        For i:=1 to length(St) do
                If St[i] <> #32 then Write(St[i]);
        Readln
End.

Câu 4:

Program Xau;
Uses crt;
Var St: String;
    res, i: longint;

Begin
        Clrscr;
        Write('Nhap xau: '); Readln(St);
        res:=0;
        For i:=1 to length(St) do
                If St[i] in ['0'..'9'] then inc(res);
        Write(res);
        Readln
End.

Câu 5:

Program Xau;
Uses crt;
Var St: String;
    i: longint;

Begin
        Clrscr;
        Write('Nhap xau: '); Readln(St);
        For i:=1 to length(St) do
                If not (St[i] in ['0'..'9']) then Write(St[i]);
        Readln
End.