Topic 4 Computational Thinking

Sequential search

ARRAYNAME = (9,2,6,5,8,1)

TARGET = 6

FOUND = False

INDEX = 0

loop for i from 0 to ARRAYNAME.length-1

  if ARRAYNAME[i] = TARGET then

     FOUND = True

     INDEX = i

  end if

end loop

output INDEX

if FOUND = False then

   output “Target not found”

end if

Binary search

ARRAYNAME = (9,2,6,5,8,1)

TARGET = 6

LOW = 0

HIGH = ARRAYNAME.length - 1

FOUND = FALSE

loop while LOW <= HIGH

  MID = (LOW + HIGH) div 2

  if ARRAYNAME[MID] = TARGET then

    output MID

    FOUND = True

  else if TARGET > ARRAYNAME[MID] then

    LOW = MID + 1

  else

    HIGH = MID - 1

  end if

end loop

if FOUND = False then

output "Target not found"

end if

Bubble sort

ARRAYNAME = (3,4,2,1,9,8)

for i from 1 to ARRAYNAME.length

 for j from 0 to ARRAYNAME.length-1

  if ARRAYNAME[j]>a[j+1]

   swap( a[j], a[j+1] )

  end if

 end for loop

end for loop

output ARRAYNAME

Selection sort

ARRAYNAME = (9,2,6,5,8,1)

loop for i from 0 to ARRAYNAME.length-2

  MIN = i

  loop for j from i+1 to ARRAYNAME.length-1

    if ARRAYNAME[j] < ARRAYNAME[MIN] then

       MIN = j

  end loop

  if MIN != i then

    swap(a[i],a[MIN])

  end if

end loop