Bài giảng dap an HSG 11

Bµi 1:
Program xau;
var
s:string;
i:Byte;
Begin
Write('Moi nhap xau: ');
Readln(s);
Writeln('Xau vua nhap: ',s);
Write('Xau nguoc lai: ');
For i:=length(s) downto 1 do write(s[i]);
Readln;
End.
Bµi 2:
Program mang2chieu;
Var
A:array[1..10,1..10] of integer;
Max:integer;
N,i,j: Byte;
Begin
Write('Moi nhap N=');
Readln(N);
Writeln('Moi nhap cac phan tu mang:');
For i:=1 to N do
For j:=1 to N do
Begin
write('A[',i,',',j,',',']');
readln(A[i,j])
End;
Max:=A[1,1];
Write('Cac phan tu tren duong cheo chinh: ');

For i:=1 to N do
For j:=1 to N do
Begin
if i=j then write(a[i,j],' ');
if Max<A[i,j] then Max:=A[i,j];
end;
Writeln;
Writeln('Gia tri lon nhat= ',Max);
Write('Vi tri: ');
For i:=1 to N do
For j:=1 to N do
If A[i,j]=Max then write('(',i,',',j,')');
Readln
End.
Bµi 3:
Program Mang1chieu;
Var
A:array[1..50] of integer;
S:integer;
N,i,dau, cuoi: Byte;
Begin
Write('Moi nhap N=');
Readln(N);
Writeln('Moi nhap cac phan tu mang:');
For i:=1 to N do
Begin
write('A[',i,']=');
readln(A[i]) ;
End;
S:=0; i:=1;

While A[i]<>0 do i:=i+1;
Dau:=i;
i:=N;
While A[i]<>0 do i:=i-1;
Cuoi:=i;
For i:=dau to cuoi do S:=S+A[i];
Writeln('Tong cac so giua 2 so 0= ',S);
Readln
End.
Bµi 4:
Program So_hoan_thien;
Var
R,S,i,j,d:Word;
T:Word;
Begin
Write('Moi nhap R, S:');
Readln(R,S);
Write('Cac so hoan thien: ');
d:=0;
For i:=R to S do
Begin
T:=0;
For j:=1 to i-1 do
if i mod j=0 then T:=T+j;
if T=i then
Begin
d:=d+1;
write(i,' ');
end;
End;

If d=0 then Write('khong tim thay');
Readln;
End.