java data structures interview questions

Stackelement see the implementation of the stackPackage Com.lip.datastruture.stack;public class QueueOperation Result:Implementation of the queue of data structures (JAVA)

' (', directly into the stack, if ') ', out of the stack and sequential output operator until the first ' (', the first encountered ' ('), but not the output, if the arithmetic character, the top element of the stack and the current element precedence: If the top of the stack operator precedence >= the current element priority , out of the stack and sequential output operator until the top element of the stack priority 5, repeat the 3rd until the expression scan is complete.6, sequentially out

public int getheight () {if (this==null) return 0;if (This.leftnode = = NULL This.rightnode = = null) retu RN 1;int lheight = This.leftNode.getHeight (); int rheight = This.rightNode.getHeight (); return lheight > Rheight? Lheight + 1:rheight + 1;}4. Layer k of the print tree (recursive implementation)Principle: Can be understood as the print root of the K-layer, that is, print the root of the child's k-1 layer, when k=0, can be directly printed outPrint the level layer of a tree public void P

()) { CharCH =Thestack.pop (); Output= output +ch; } returnoutput; } } classReverseapp { Public Static voidMain (string[] args)throwsIOException {String input, output; while(true) {System.out.print ("Enter A string:"); System.out.flush (); Input=getString1 (); if(Input.equals ("")) { Break; } reverser Thereverser=Newreverser (input); Output=Thereverser.dorev (); System.out.println ("Reversed:" +output); } } Public StaticString getString

initialization does not require allocating space, but it needs to allocate a pointer field, there is a structural overhead, but there is no length limit. Application recommendations:?? If the use of the stack element changes unpredictable, sometimes very small, sometimes very large, then it is best to use the chain stack, conversely, if its change in the controllable range, it is recommended to use a sequential stack is better.The reason for using the stack: the introduction of the stack s

this time we go on to look at the Java data structure vectors (vector) Stack (stack). The first is the vector, vectors (vector) classes are very similar to the traditional array, but the size of the vector can be changed dynamically according to the need. As arrays, the elements of a vector object can also be accessed through an index. The main advantage of using the vector class is that when you create an

more additions and deletions: LinkedList104 query MORE: ArrayList the I don't know, just use ArrayList.106 I don't know, just use ArrayList.107 108 3: Common methods of collection and Traverse mode 109 　　 Collection: the Add ()111 Remove () the contains ()113 iterator () the size () the the 　　　 Traversal:　117 Enhanced for118 iterators119 -|--List121 get ()122 123 Traversal:124 General for the|--Set126 127 　　 Map: - put ()129 Remove () the Con

Stack implementation of data structures (JAVA) (I) // Stack top element public class StackElement {Private StackElement NextElement; private T data; public StackElement (T data) {this. data =

("Lookup data does not exist"); the return NULL; the } + -System.out.println ("Find successful, data is:" + This. list[p]); the return This. list[p];Bayi } the the //Sequential Table Size - Public intSizeOf () { - return This. Listlen; the } the the Public voidPrint () { theSystem.out.print ("["); - for(inti = 0; I This. list.length;

if(Head.next.data.equals (key)) { theSystem.out.print ("Query node:" + key + ","); theSystem.out.print ("Query node predecessor node is:" + Head.data + ","); the if(Head.next.next! =NULL) {98SYSTEM.OUT.PRINTLN ("Query node post node is:" +head.next.next.data); About}Else { -SYSTEM.OUT.PRINTLN ("Query node is tail node!"));101 }102 return;103 }104Head =Head.next; the }106System.out.println ("No this node!"));107

, this time will not be faster than bubble sorting.Back to top 4, summaryThe above three kinds of sorting, bubbling, selecting, inserting with large O notation all require O (N2) time level. Bubbling sorting is not generally selected, although bubbling sort writing is the simplest, but the average performance is not to choose sort and insert sort well.Select sort to reduce the number of exchanges to the lowest, but the number of comparisons is quite large. Select sort can be applied when the amo

with large O notation all require O (N2) time level. Bubbling sorting is not generally selected, although bubbling sort writing is the simplest, but the average performance is not to choose sort and insert sort well.Select sort to reduce the number of exchanges to the lowest, but the number of comparisons is quite large. Select sort can be applied when the amount of data is small and exchange data is more

;importorg.junit.before;importorg.junit.test; importcom.xingej.algorithm.datastructure.array.myarray;/*** Object-Oriented programming,** That is, the you operate is an object, not a basic data type *** @author erjun2017 November 28 Afternoon 9:59:36*/publicclassmyarraytest{privatemyarray myarray; @Before publicvoidinit () { myarray=newmyarray (); testinsert ();}// Insert data test @Test publicvoidtest (

Stacks and queues:It is generally used as a programmer's tool to assist the idea algorithm, the life cycle is shorter, the runtime is created;Access is restricted, at a particular time, only one data can be read or deleted;is an abstract structure, the internal implementation mechanism, not visible to users, such as the use of arrays, linked lists to implement the stack. Analog stack structureat the same time, only one

The enumeration (enumeration) interface, although not part of the data structure itself, is widely used in other data structure categories. The enumeration (the enumeration) interface defines a way to retrieve contiguous elements from a data structure.For example, an enumeration defines a method called Nextelement, which is used to get the next element of a

Java data structures and algorithms (iii) -- simple sorting Data alone is not enough. Data presentation often needs to be arranged in a certain order. The higher the requirement, the more complicated the sorting. This article only introduces three simple sorting types. 1) B

starts with two pointers, and two pointers point to both ends of the array. (The word "pointer" is used here to indicate the array data item, not the pointer in C + +.) The pointer on the left, Leftptr, moves to the right, while the pointer on the right, rightptr, moves to the left.In fact, leftptr initialization is at the left of the first data item, and Rightptr is on the right-hand side of the last

; 1){ - if(Peoples[index]) { incount++; - if(Count = = 3){ toPeoples[index] =false; +Count=0; -leftcount--;//minus 1 for the rest of the population. the } * } $ Panax Notoginseng //put the element under the label -index++; the + //If you have counted to the end of the array, start the number A if(Index > Len-1){ theindex = 0; + } - } $ $ for(i

; J ) {System.out.print (A[j]+ " "); } System.out.println (""); } //Bubble Sort Public voidBubblesort () {intOut , in; for(out = nElems-1, out > 1; out--) { for(in = 0; in ) { if(A[in] > a[in + 1]) {swap (in,+ 1); } } } } //Insert Sort Public voidInsertionsort () {intin, out; //Out are dividing line for(out = 1; out ) { //Remove marked item Longtemp =A[out]; //start shifts at outin =Out ; wh

) { +Temp[i] =key; -}Else { theTemp[i] = This. table[i-1];Bayi } the } the - This. Table =temp; - } the the Public intSearchindex (intkey) { the intn = key/m-1; the intStart =-1; - intLength =-1; the //Find index location the for(inti = 0; I This. Indextable.size (); i++) { the if(n = = This. Indextable.get (i). Index) {94Start = This. Indextable.get (i). Start; theLength = This. Indextable.get (i). len