Search routines (paper 2)

each item to be searched from will be checked one by one in the list until the item is found or an error is outputted

• linear • bubble sort

// perform a linear search of an array DECLARE AList : ARRAY[1:10] OF INTEGER AList <- [14, 2, 3 ,11, 1, 9, 5, 8, 10, 6] OUTPUT “List to be searched:”, AList Found <- FALSE Index <- 1 INPUT SearchItem WHILE Found = FALSE AND Index <= LENGTH(AList) DO IF AList[Index] = SearchItem THEN Found <- TRUE ELSE Index <- Index + 1 ENDIF ENDWHILE IF Found = TRUE THEN OUTPUT SearchItem, “in position”, Index, “of the list” ELSE OUTPUT “Item not found” ENDIF

it repeatedly goes through the list to be sortedd, swapping adjacent elements if they are in the wrong order

//bubble sort with flag set when no swaps are made AList <-[17, 3, 7, 15, 12, 23, 20] // get number of items in the array NumItems <- LENGTH(AList) Comparisions <- NumItems - 1 SwapMade <- TRUE WHILE Comparisons > 0 AND SwapMade = TRUE SwapMade <- FALSE FOR i <- 1 TO Comparisons IF AList[i] > AList[i + 1] THEN Temp <- AList[i] AList[i] <- AList[i + 1] AList[i + 1] <- Temp SwapMade <- TRUE ENDIF NEXT i Comparisons <- Comparisons - 1 ENDWHILE OUTPUT “Sorted list: “, AList