paper 2: algorithms 2.1

paper 2: algorithms 2.1

1. Abstraction

   • using symbols, variables ect. to represent a 'real world' problem in a computer program
   • it also removes unnecessary elements

2. decomposition

   • breaking down a large problem into smaller sub-problems
     • smaller problems are easier to solve
       • they can be independent to the other problems.
         • they can be tested independently
           • they combine to produce a full programme
             • there is not always on 1 right answer

3. algorithmic thinking

   • identifying the steps involved in solving a problem

4. computational thinking

   • the use of computers to solve problems
     • the use of computers to solve problems
       • development of algorithms to solve problems.
         • using abstraction, decomposition and algorithmic thinking

5. linear search

   • each item in the list is checked in order
   • the binary search only works if data is in order
     • if it is not in order you can use linear search
       • check the first value
         • IF it is the first value you are looking for: you win
           • ELSE move to and check the next value
             • REPEAT UNTIL you have checked all the elements until you find the value your looking for

6. binary search

   • an ordered list is divided in 2 with each comparison
   • the list needs to be in order
     • take the middle value
       • compare to the value you are looking for
         • IF it is the value you are looking for: you win
           • ELSEIF it is larger than the one you are looking for: take the values to the left of the middle value
             • if it is smaller than the one you are looking for: take the value to the right of the middle value
               • repeat with new list

7. bubble sort

   • moving through a list repeatedly, swapping elements that are in the wrong order
     • take the first element and second element from the list
       • compare them
         • IF element 1 > element 2 THEN... swap them
           • ELSE do nothing
             • REPEAT: move along the list to the next pair / IF no more elements: go to 1/ ELSE go yo 2
               • until: you have moved through the entire list and not made any changes

8. merge sort

   • a list is split into individual lists, these are then combined (2 lists at a time )
   • split all elements into individual lists
     • compare the first elements in both lists
       • put the smallest into a new list
         • compare the next element of 1 list with the second element of the second list
           • put smallest into new list
             • repeat until merged
   • split a list into individual lists
     • merge the lists in pairs, putting the smallest first.
       • merge the lists
         • keep merging until it is in order

9. list

   • a set of data

10. insertion sort

    • each items is take in turn, compare to the items in a sorted lists and placed in the correct position
      • element 1 is a 'sorted' list
        • the rest of the elements are an ' unsorted' list
          • josh holland

11. ordered list

    • elements are arranged in sequence

12. unordered list

13. algorithm

    • the series of steps to solve a problem or perform an action

14. flowchart

    • a diagram that shows the inputs, outputs and processes in an algorithm

15. process

    • an action that takes place

16. pseudocode

    • simplified programming code that is not language specific, used to design algorithms