uses crt;

var a:array[1..300]of integer;

i,n,dem,kt,t:integer;

begin

clrscr;

write('Nhap n='); readln(n);

for i:=1 to n do 

  begin

write('A[',i,']='); readln(a[i]);

end;

dem:=0;

for i:=1 to n do 

  if a[i] mod 3=0 then inc(dem);

t:=abs(a[2]-a[1]);

kt:=0;

for i:=1 to n do 

if t<>abs(a[i]-a[i-1]) then 

begin

kt:=1;

break;

end;

if kt=0 then writeln('Day la cap so cong')

else writeln('Day khong la cap so cong');

readln;

end.

uses crt;

var a:array[1..300]of integer;

i,n,t,tb:integer;

begin

clrscr;

write('Nhap n='); readln(n);

for i:=1 to n do 

  begin

write('A[',i,']='); readln(a[i]);

end;

t:=0;

for i:=1 to n do 

  if i mod 2=1 then t:=t+a[i];

tb:=0;

for i:=1 to n do 

  tb:=tb+a[i];

writeln('Tong cac phan tu cua day o vi tri le la: ',t);

writeln('Trung binh cong cua day la: ',tb/n:4:2);

readln;

end.

uses crt;

var a:array[1..100]of integer;

i,n,dem:integer;

begin

clrscr;

write('Nhap n='); readln(n);

for i:=1 to n do 

begin

write('A[',i,']='); readln(a[i]);

end;

dem:=0;

for i:=1 to n do 

  if a[i]>0 then inc(dem);

writeln(dem);

readln;

end.

Câu 2: 

uses crt;

var a:array[1..100]of integer;

i,n,t1,t2:integer;

begin

clrscr;

write('Nhap n='); readln(n);

for i:=1 to n do 

begin

write('A[',i,']='); readln(a[i]);

end;

t1:=0;

t2:=0;

for i:=1 to n do 

begin

if a[i] mod 2=0 then t1:=t1+a[i]

else t2:=t2+a[i];

end;

writeln('Tong cac so chan la: ',t1);

writeln('Tong cac so le la: ',t2);

readln;

end.

3333ffffgvvvv

uses crt;

const fi='songuyen.dat';

var f1:text;

a:array[1..100]of integer;

i,n,t:integer;

begin

clrscr;

assign(f1,fi); reset(f1);

readln(f1,n);

for i:=1 to n do 

  read(f1,a[i]);

t:=0;

for i:=1 to n do 

  t:=t+a[i];

writeln(t);

close(f1);

readln;

end.

function max(a,b,c:integer):integer;

begin

max:=a;

if max<b then max:=b;

if max<c then max:=c;

end;

const fi='input.txt';

fo='output.txt';

var f1,f2:text;

a,b:integer;

begin

assign(f1,fi); reset(f1);

assign(f2,fo); rewrite(f2);

readln(f1,a,b);

writeln(f2,a+b);

close(f1);

close(f2);

end.

uses crt;

var a:array[1..1000]of integer;

n,i,dem:integer;

begin

clrscr;

write('Nhap n='); readln(n);

for i:=1 to n do 

  begin

write('A[',i,']='); readln(a[i]);

end;

dem:=0;

for i:=1 to n do 

  if a[i] mod 2=0 then inc(dem);

writeln(dem);

readln;

end.

Bài 1: 

uses crt;

var st:string;

i,d:integer;

begin

clrscr;

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

d:=length(st);

for i:=1 to d do 

  st[i]:=upcase(st[i]);

writeln(st);

readln;

end.