Chapter 6 _ implementing priority queue

Public class priority_queue {// storage array private int A []; // heap size private int pile_size = 0; // If a specified value is found, return-1 private int not_find =-1; // Private int increat_capcity = 20; // heap container size Private Static int int_num = 20; // The constructor 1 _ does not specify the heap container size. The container size is set to the default size. Value: int_num: 20; Public priority_queue () {This (int_num );} // constructor 2__ specifies the size of the heap container public priority_queue (INT capcity) {A = new int [capcity];} // inserts a value into the container. Considering multithreading, so join synchronizedpublic sync Hronized void insert (INT value) {If (getheap_size () =. length) {increate_capcity ();} A [pile_size] = value; query_suitable_index (pile_size ++);} // modify the value of public synchronized Boolean modify (INT index, int value) {If (index <0 | index> pile_size) {return false;} If (value <A [Index]) {return false ;} A [Index] = value; query_suitable_index (INDEX); return true;} // modify or add elements. As a result, the container does not meet the heap nature, so it needs to be initialized ", make the container meet the public void query_s of the heap nature Uitable_index (INT index) {While (parent (INDEX )! = Not_find & index> = 1 & A [Parent (INDEX)] <A [Index]) {int exchange = A [Index]; A [Index] = A [Parent (INDEX)]; A [Parent (INDEX)] = exchange; Index = parent (INDEX );}} // increase the container size public void increate_capcity () {int [] B = new int [. length + increat_capcity]; for (INT I = 0; I <. length; I ++) {B [I] = A [I] ;}a = B ;}// obtain the number of container elements. Public int getheap_size () {return pile_size ;} // get the left child public int left_chiren (int I) {int left = I * 2 + 1; retu RN (left <pile_size )? Left: not_find;} // get the right child public int right_chiren (int I) {int right = I * 2 + 2; Return (right <pile_size )? Right: not_find;} // get the Parent and Child Nodes public int parent (int I) {int parent = (I-1)/2; Return (parent> = 0 )? Parent: not_find;} // initialize the heap container from the specified node "! Public void max_pile (int I) {int left_chiren = left_chiren (I); int right_chiren = right_chiren (I); int largest; If (left_chiren! =-1 & A [I] <A [left_chiren]) {largest = left_chiren;} else {largest = I;} If (right_chiren! =-1 & A [Largest] <A [right_chiren]) {largest = right_chiren;} If (largest! = I) {int largetvalue = A [Largest]; A [Largest] = A [I]; A [I] = largetvalue; max_pile (largest );}} // sort the heap public void heap_sort () {// sort from small to large for (INT I = pile_Size-1; I> = 1; I --) {int exchange = A [I]; A [I] = A [0]; A [0] = exchange; pile_size --; max_pile (0 );}} // obtain the largest public int getmax () {return a [0];} // obtain the largest element in the heap and delete the largest public int extract_max () {If (pile_size <1) {return not_find;} int max = A [0]; A [0] = A [pile_size --]; max_pile (0); Return Max ;} // print @ overridepublic string tostring () {stringbuilder sb = new stringbuilder (); For (INT I = 0; I <pile_size; I ++) Sb. append (A [I] + ""); return sb. tostring () ;}// test public static void main (string [] ARGs) {priority_queue pile = new priority_queue (); system. out. println ("--------------- test the insert () method ------------------------"); For (INT I = 1; I <5; I ++) {pile. insert (I); system. out. println ("Add new element:" + I); system. out. println (pile);} system. out. println ("--------------- test the extract_max () method -------------------"); system. out. println ("Maximum number of heap containers:" + pile. extract_max (); system. out. println ("Delete the maximum number in the heap, and the container changes to:"); system. out. println (pile );}}

Output:

--------------- Test the insert () method --------------------------
Add new elements: 1
1
Add new elements: 2
2 1
Add new elements: 3
3 1 2
Add new elements: 4
4 3 2 1
--------------- Test the extract_max () method ---------------------
Maximum number of heap containers: 4
Delete the maximum number in the heap. Then, the container changes:
3 0 2

Chapter 6 _ implementing priority queue