Sorts on the AP Exam Insertion Sort

Learning Objectives Review the Selection Sort Be able to describe the Insertion Sort: Speed, Stability, How it works Be able to read code for the Insertion Sort Be able to write a program that uses the Insertion Sort

Selection Sort Review In note books answer the following Speed Stable ? How does it work When should you use a Selection Sort? Sort the following, showing the values after each pass until sorted. High Low 20 10 15 8 2 40 1

Insertion sort How it works Example Low High 8 6 7 3 15 1 5 Stability 8 6 7 3 15 1 5 Stability Speed Your turn High Low 8 2 5 3 9 4 6 1 7 Dummy, slide, back Stable O(n2)

Insertion Sort // a is the name of the array // nElems stores the number of elements being sorted // This example is for sorting an array of ints int in, out; for(out=1; out<nElems; out++) // out is dividing line { int dummy = a[out]; // dummy Need to modify for sorting different types in = out; // start shifts at out while(in>0 && a[in-1] >= dummy) // until one is smaller, a[in] = a[in-1]; // Slide: shift item right, in--; // go left one position } a[in] = dummy; // Back: insert marked item } // end for

First Program Check for Understanding import java.util.Scanner; // program uses class Scanner public class InsertionSort { public static void main(String args[]) String[] names = new String[5]; String name; // create Scanner to obtain input from command window Scanner input = new Scanner( System.in ); for (int count = 0 ; count < names.length; count++) System.out.println("Please enter a name"); names[count] = input.next(); } for (int j=0; j<names.length; j++) System.out.println(names[j]); //Insert Sort Code here System.out.println("The names ..."); for (String nam: names) // For each String nam in the array names. System.out.println(nam); First Program Check for Understanding Enter this into BlueJ and test to make sure it is sorting.

Insertion Sort Program Phoney book for an unknown # (<100) Names Write a program with a menu with the following choices. Add a name: Semantics of a while loop. Method or in main body. Show all names : Method Sort the names: Method using the Insertion Sort Find a name. The user will enter a name and the program will tell if the name is in your list or not. Method or main body. Pushes: Figure out how to store a name and phone number. This will make the program a bit more useful. Enhance the find part to handle some sort of misspelling. Extra letters, Case insensitive, … Describe what errors your method will be able to handle. Create a class People that will have fields for name, phone, and email. Create an array of People rather than an array of String for the above program.

Shell for the Selection Sort program. import java.util.Scanner; public class SortOfFun { public static void main(String [] args) } public static void insertionSort(String [] unsortedArray) public static void show(String [] arrayToShow) Shell for the Selection Sort program.