![LINEAR SEARCH: SIMPLE
Pseudocode:
INITIALISE colours array
ASK user FOR search_item
REPEAT with position FOR number of items in array
IF colours[position] = search_item THEN
DISPLAY “Search item found in position ” & position](https://image.slidesharecdn.com/standardalgorithms-200411134743/85/Standard-Algorithms-3-320.jpg)
![LINEAR SEARCH: IMPROVED
INITIALISE colours array
SET found TO false
SET position TO 0
ASK user FOR search_item
WHILE position < array length AND found is false DO
IF colours[position] = search_item THEN
SET found TO true
ELSE
ADD 1 TO position
IF found is true THEN
DISPLAY ‘Colour found in position’ & position + 1
ELSE
DISPLAY ‘Colour not found’](https://image.slidesharecdn.com/standardalgorithms-200411134743/85/Standard-Algorithms-6-320.jpg)
![COUNT OCCURRENCES
• Count occurrences will count the number of times a specific value
appears in an array
• For example:
[‘A’, ‘B’, ‘C’, ‘C’, ‘A’, ‘A’, ‘B’]
The letter A appears 3 times in the array](https://image.slidesharecdn.com/standardalgorithms-200411134743/85/Standard-Algorithms-8-320.jpg)
![COUNT OCCURRENCES
Pseudocode:
INITIALISE colours array
SET occurrences to 0
ASK user FOR search_item
REPEAT WITH counter FOR array length
IF colours[counter] = search_item THEN
ADD 1 TO occurrences
DISPLAY occurrences](https://image.slidesharecdn.com/standardalgorithms-200411134743/85/Standard-Algorithms-9-320.jpg)
![FIND MAXIMUM
Pseudocode:
INITIALISE heights array
SET maximum TO first array element
REPEAT WITH counter FOR array length
IF heights[counter] > maximum THEN
SET maximum TO heights[counter]
DISPLAY maximum](https://image.slidesharecdn.com/standardalgorithms-200411134743/85/Standard-Algorithms-12-320.jpg)
![FIND MINIMUM
Pseudocode:
INITIALISE heights array
SET minimum TO first array element
REPEAT WITH counter FOR array length
IF heights[counter] < minimum THEN
SET minimum TO heights[counter]
DISPLAY minimum](https://image.slidesharecdn.com/standardalgorithms-200411134743/85/Standard-Algorithms-14-320.jpg)
Standard Algorithms
- 1. STANDARD ALGORITHMS Higher Computing Science
- 2. LINEAR SEARCH • Linear search searches an array for a specific value • If the value is found it will return its position in the array • If the value is not found it will return a message to say so
- 3. LINEAR SEARCH: SIMPLE Pseudocode: INITIALISE colours array ASK user FOR search_item REPEAT with position FOR number of items in array IF colours[position] = search_item THEN DISPLAY “Search item found in position ” & position
- 5. LINEAR SEARCH: SIMPLE Issues: 1. Continues through loop when item found (inefficient) 2. No message if item not found 3. Displays array position rather than actual position 1st item = position 0 2nd item = position 1 etc 4. Loop fixed - 6 times
- 6. LINEAR SEARCH: IMPROVED INITIALISE colours array SET found TO false SET position TO 0 ASK user FOR search_item WHILE position < array length AND found is false DO IF colours[position] = search_item THEN SET found TO true ELSE ADD 1 TO position IF found is true THEN DISPLAY ‘Colour found in position’ & position + 1 ELSE DISPLAY ‘Colour not found’
- 8. COUNT OCCURRENCES • Count occurrences will count the number of times a specific value appears in an array • For example: [‘A’, ‘B’, ‘C’, ‘C’, ‘A’, ‘A’, ‘B’] The letter A appears 3 times in the array
- 9. COUNT OCCURRENCES Pseudocode: INITIALISE colours array SET occurrences to 0 ASK user FOR search_item REPEAT WITH counter FOR array length IF colours[counter] = search_item THEN ADD 1 TO occurrences DISPLAY occurrences
- 11. FIND MAXIMUM / MINIMUM • Find maximum will return the largest value in a list • Find minimum will return the smallest value in a list • Algorithms are almost identical, the main difference is in the IF statement: • > comparison (maximum) • < comparison (minimum)
- 12. FIND MAXIMUM Pseudocode: INITIALISE heights array SET maximum TO first array element REPEAT WITH counter FOR array length IF heights[counter] > maximum THEN SET maximum TO heights[counter] DISPLAY maximum
- 14. FIND MINIMUM Pseudocode: INITIALISE heights array SET minimum TO first array element REPEAT WITH counter FOR array length IF heights[counter] < minimum THEN SET minimum TO heights[counter] DISPLAY minimum