Chapter 7 Algorithm Design And Problem Solving: Unit 7.4: Standard Methods Of Solution

Totalling Counting Finding the max, min and average (mean) values Searching using a linear search Sorting using a bubble sort

Keeping a total that values are added to. Example: Total <– 0 FOR Counter <– 1 TO ClassSize Total <– Total + StudentMark[Counter] NEXT Counter

Keeping a count of the number of times an action is performed. Example: PassCount <– 0 FOR Counter <– 1 TO ClassSize INPUT StudentMark IF StudentMark > 50 THEN PassCount <– PassCount + 1 NEXT Counter Count <– Count + 1 Can also be used to count down.

Finding the largest and smallest values in a list. Example: MaximumMark <– 0 MinimumMark <– 100 FOR Counter <– 1 TO ClassSize IF StudentMark[Counter] > MaximumMark THEN MaximumMark <– StudentMark[Counter] ENDIF IF StudentMark[Counter] < MinimumMark THEN MinimumMark <– StudentMark[Counter] ENDIF NEXT Counter Calculating the average (mean) of all values in a list is an extension of the totalling method. Example: Total <– 0 FOR Counter <– 1 TO ClassSize Total <– Total + StudentMark[Counter] NEXT Counter Average <– Total / ClassSize

A search is used to check if a value is stored in a list, performed by systematically working through the items in the list. Linear search inspects each item in a list in turn to see if the item matches the value searched for. Example: OUTPUT “Please enter name to find “ INPUT Name Found <– FALSE Counter <– 1 REPEAT IF Name = StudentName[Counter] THEN Found <– TRUE ELSE Counter <– Counter + 1 ENDIF UNTIL Found OR Counter > ClassSize IF Found THEN OUTPUT Name, “ found at position “, Counter, “ in the list.” ELSE OUTPUT Name, “ not found.” ENDIF

Each element is compared with the next element and swapped if the elements are in the wrong order, starting from the first element and finishing with the next-to-last element. Example: First <– 1 Last <– 10 REPEAT Swap <– FALSE FOR Index <– First TO Last - 1 IF Temperature[Index] > Temperature[Index + 1] THEN Temp <– Temperature[Index] Temperature[Index] <– Temperature[Index + 1] Temperature[Index + 1] <– Temp Swap <– TRUE ENDIF NEXT Index Last <– Last - 1 UNTIL (NOT Swap) OR Last = 1