CHALLENGE

ACTIVITY

13.2.1: Linked list negative values counting.

Assign negativeCntr with the number of negative values in the linked list.

// ===== Code from file IntNode.java ===== public class IntNode { private int dataVal; private IntNode nextNodePtr;

public IntNode(int dataInit, IntNode nextLoc) { this.dataVal = dataInit; this.nextNodePtr = nextLoc; }

public IntNode(int dataInit) { this.dataVal = dataInit; this.nextNodePtr = null; }

/* Insert node after this node. * Before: this -- next * After: this -- node -- next */ public void insertAfter(IntNode nodePtr) { IntNode tmpNext;

tmpNext = this.nextNodePtr; // Remember next this.nextNodePtr = nodePtr; // this -- node -- ? nodePtr.nextNodePtr = tmpNext; // this -- node -- next return; }

// Grab location pointed by nextNodePtr public IntNode getNext() { return this.nextNodePtr; } public int getDataVal() { return this.dataVal; } } // ===== end =====

// ===== Code from file CustomLinkedList.java ===== import java.util.Random;

public class CustomLinkedList { public static void main (String [] args) { Random randGen = new Random(); IntNode headObj; // Create intNode objects IntNode currObj; IntNode lastObj; int i = 0; // Loop index int negativeCntr = 0;

headObj = new IntNode(-1); // Front of nodes list lastObj = headObj;

for (i = 0; i < 10; ++i) { // Append 10 rand nums int rand = randGen.nextInt(21) - 10; currObj = new IntNode(rand); lastObj.insertAfter(currObj); // Append curr lastObj = currObj; // Curr is the new last item }

currObj = headObj; // Print the list while (currObj != null) { System.out.print(currObj.getDataVal() + ", "); currObj = currObj.getNext(); } System.out.println("");

currObj = headObj; // Count number of negative numbers while (currObj != null) {

/* Your solution goes here */

currObj = currObj.getNext(); } System.out.println("Number of negatives: " + negativeCntr);

return; } } // ===== end =====