Двумерный массив. Заменить все отрицательные числа нулями. Подсчитать сумму положительных

var
  a: array[1..3, 1..3] of integer;
  i, j, sum: integer;
 
begin
  sum := 0;
  for i := 1 to 3 do
    for j := 1 to 3 do
      read(a[i][j]);
  for i := 1 to 3 do
  begin
    for j := 1 to 3 do
      write(a[i][j]:4);
    writeln;
  end;
  writeln;
  for i := 1 to 3 do
  begin
    for j := 1 to 3 do
    begin
      if a[i][j] < 0 then a[i][j] := 0;
      inc(sum, a[i][j]);
      write(a[i][j]:4);
    end;
    writeln;
  end;
  writeln;
  writeln(sum);
end.

var
  a: array[1..8, 1..5] of integer;
  i, j: integer;
 
begin
  for i := 1 to 8 do
  begin
    for j := 1 to 5 do
    begin
      a[i][j] := random(3) - 1;
      write(a[i][j]:3);
    end;
    writeln;
  end;
  writeln;
  writeln(8 * 5);
end.

const
  N=15;
  A:array[1..N] of integer =(1,5,12,15,16,18,33,34,36,39,40,44,45,46,50);
var
  i,v,left,right,middle:integer;
begin
  writeln('The source array is:');
  for i:=1 to N-1 do write(A[i],', ');
  writeln(A[N],'.');
  write('Input a value for searching: ');
  readln(v);
 
  left:=1;
  right:=N;
  repeat
    middle:=left+(right-left) div 2;
    if v<A[middle] then right:=middle else left:=middle;
    writeln('It should be somewere between ',left,' and ', right);
  until right-left<=1;
  if v=A[left] then writeln('Requested value was found at position ',left)
    else if v=A[right] then writeln('Requested value was found at position ',right)
      else writeln('Requested value is NOT found');
  readln;
end.

program asd;
uses crt;
var a: array [1..5] of integer;
i,n,z,w1,w2:integer;
f:boolean;
begin
clrscr;
randomize;
write ('Ishodnyi vektor: ');
for i:= 1 to 5 do
a[i]:= random (10);
for i:= 1 to 5 do
write (a[i],';');
writeln;
write ('Vvedite iskomyi element: ');
readln  (n);
w1:=1;
w2:=5;
f:=false;
repeat
i:= (w1+w2) div 2;
if a[i]=n then f:=true
else
if a[i]>n then w1:=i+1;
w2:=i-1;
until
(f) or (w1>w2);
if f=true then
write ('Iskomyi element: ',n,', kotoryi imeet poziciyou: ',i)
else
writeln ('Net tut takogo');
end.