program SortBinaryArray;
const
N = 9; // Size of the binary array
type
IntArray = array[1..N] of integer;
// Function to sort an array containing only 0s and 1s
procedure SortBinaryArray(var arr: IntArray);
var
left, right, temp: integer;
begin
left := 1; // Index to track the left side
right := N; // Index to track the right side
while left < right do
begin
// If the left Index is at 0, move it forward
if arr[left] = 0 then
begin
writeln('left: ', left);
inc(left);
end
// If the right Index is at 1, move it backward
else if arr[right] = 1 then
begin
writeln('right: ', right);
dec(right);
end
// If left is 1 and right is 0, swap them
else
begin
temp := arr[left];
arr[left] := arr[right];
arr[right] := temp;
writeln('swap() left: ', left, ' right: ', right);
inc(left);
dec(right);
end;
end;
end;
var
arr: IntArray;
i: integer;
begin
// Input: Binary array
arr[1] := 1;
arr[2] := 0;
arr[3] := 1;
arr[4] := 0;
arr[5] := 1;
arr[6] := 0;
arr[7] := 0;
arr[8] := 1;
arr[9] := 0;
// Sort the binary array
SortBinaryArray(arr);
// Output the sorted array
write('Sorted array: ');
for i := 1 to N do
write(arr[i], ' ');
end.
(*
run:
swap() left: 1 right: 9
left: 2
right: 8
swap() left: 3 right: 7
left: 4
swap() left: 5 right: 6
Sorted array: 0 0 0 0 0 1 1 1 1
*)
