begin for i := 1 to 15 do begin write('a[', i, '] = ');readln(a[i]); if i mod 3 = 0 then s := s + a[i]; end; writeln('Сумма элементов, индексы которых кратны 3 = ', s); end.
begin for i := 1 to 15 do begin a[i] := random(100);write(a[i]:4); end; writeln; for i := 1 to 15 do begin if i mod 2 = 0 then a[i] := a[i] * 2; write(a[i]:4); end; end.
var a: array[1..m] of integer; i, n, k, tmp: integer;
begin write('число элементов : '); readln(n); for i := 1 to n do begin write('a[', i, '] = ');readln(a[i]); end; repeat write('Введите к (k<>1 и k<>n)'); readln(k); if (k = 1) or (k = n) then writeln('Ошибка, повторите ввод'); until (k <> 1) and (k <> n); for i := 1 to n do write(a[i]:4);writeln; tmp := a[k - 1];a[k - 1] := a[k + 1];a[k + 1] := tmp; for i := 1 to n do write(a[i]:4); end.