Q4 part 1
int bitrev(int x)
{ int size = 8*sizeof(int);
  unsigned int mm = 1<<(size-1),
      lm = 1;
      ans = 0;
  for (i = 0; i < size; i += 1)
  { if (x & lm)
      ans |= mm;
    mm >>= 1;
    lm <<= 1; }
  return ans; }

not quite the way:
  temp = 0;
  mask = 1;
  for (i = 0; i < size; i += 1)
  { int bit = x & mask;
    temp = temp + bit;
    temp <<= 1;
    x >> = 1; }

Q4 part b
  on the board.

Q6

#!/bin/tcsh
# this file is named del
set filename = $argv[1]
shift argv
foreach dir ( $argv )
  set f = $dir/$filename
  if ( -f $f ) then
    rm $f
    if ( $status ) echo "could not delete "$f
  else if ( -d $f ) then
    del $filename $f
  endif
end



#!/bin/tcsh
# this file is named del
set filename = $argv[1]
shift argv
foreach dir ( $argv )
  foreach file ( $dir )
    if (-f $file) then
      if ($file == $filename) then
        rm $dir/$file  
      endif
    endif
  end
end
   
#ifndef ssss