Unit 2.1 - Algorithms

Unit 2.1 - Algorithms

1. Computational Thinking

   • Computational Thinking consists of the use of computers to solve problems, developing algorithms to solve problems and using abstraction, decomposition and algorithmic thinking
   • Step 1 - Decomposition - Breaking down a large problem into smaller sub-problems
   • Step 2 - Abstraction - Removing irrelevant details and info and using variables and symbols to represent real world problems
   • Step 3 - Pattern Recognition - Looking for similarities between current and old problems
   • Step 4 - Algorithmic Thinking - Identifying the steps involved in solving a problem

2. Linear Search - Each item in the list is checked in order - Not Sorted

   • Step 1 - Check the first value
   • Step 2 - IF it is the value you're looking for - celebrate and stop
   • Step 3 - ELSE move on & check the next value
   • Step 4 - Repeat until you have checked all variables

3. Binary Search - An ordered list is divided in 2 with each comparison - Sorted

   • Step 1 - Take the middle value, compare to value your looking for
   • Step 2 - IF it is the value you're looking for - celebrate & stop
   • Step 3 - ELIF it is larger than the one you're looking for, take the values to the left, ELIF it is smaller than the value you're looking for, take the values to the right
   • Step 4 - Repeat with the new list

4. Bubble Sorting - Moving through a list repeatedly, swapping elements that are not in order

   • Step 1 - Take first two elements from list
   • Step 2 - Compare them
   • Step 3 - IF element > Element 2, swap them. ELSE - Do nothing
   • Step 4 - Repeat: Move along the list to the next pair until you have made no changes to the list

5. Merging Sort - Two lists are split into individual elements, these lists are combined 2 elements at a time

   • Step 1 - Split both lists into individual elements
   • Step 2 - Compare the first element in both lists
   • Step 3 - Put the smallest in the new list
   • Step 4 - Compare the next element of 1 list with the second element of the 2nd list
   • Step 5 - Put the smallest into the new list and repeat until merged

6. Insertion Sort - Each item is taken in turns, compared to the items in a sorted list and but into the right order

   • Step 1 - Compare the first element of the unsorted list to each element of the sorted list
   • Step 2 - If is smaller, put it in front of that element
   • Step 3 - ELIF it is larger, compare with the next
   • Step 4 - ELIF there are no more elements in the sorted list, put into final position
   • Step 5 - Repeat until all elements in the unsorted list are in the sorted list