Bài 52:
program solon_nhat;
uses crt;
var n,m:longint;
max,vt,d:byte;
begin
clrscr;
write('Nhap n: '); readln(n);
d:=0; m:=n;
while m>0 do
begin
d:=d+1;
m:=m div 10;
end;
max:=0; vt:=0;
while n>0 do
begin
if (n mod 10>=max) and (d mod 2=1) then
begin
max:=n mod 10;
vt:=d;
end;
d:=d-1;
n:=n div 10;
end;
write('Chu so lon nhat la: ',max,' voi vi tri la: ',vt);
readln;
end.
Bài 53:
program so_le;
uses crt;
var n:longint;
max,k:byte;
begin
clrscr;
write('Nhap n: '); readln(n);
max:=0;
while n>0 do
begin
k:=n mod 10;
if (k>max) and (k mod 2=1) then
max:=k;
n:=n div 10;
end;
if max=0 then write(-1) else write(max);
readln;
end.
Bài 54:
program so_chan;
uses crt;
var n:longint;
min,k:byte;
begin
clrscr;
write('Nhap n: '); readln(n);
min:=9;
while n>0 do
begin
k:=n mod 10;
if (k<min) and (k mod 2=0) then min:=k;
n:=n div 10;
end;
if min=9 then write(-1) else write(min);
readln;
end.
