MHB Linked list negative values counting.

[Teh]

I am having trouble with this program with negativeCntr . Any one explain what i am doing wrong and guide me please.

[CODE]#include <iostream>
#include <cstdlib>
using namespace std;

class IntNode {
public:
   IntNode(int dataInit = 0, IntNode* nextLoc = 0);
   void InsertAfter(IntNode* nodePtr);
   IntNode* GetNext();
   int GetDataVal();
private:
   int dataVal;
   IntNode* nextNodePtr;
};

// Constructor
IntNode::IntNode(int dataInit, IntNode* nextLoc) {
   this->dataVal = dataInit;
   this->nextNodePtr = nextLoc;
   return;
}

/* Insert node after this node.
 * Before: this -- next
 * After:  this -- node -- next
 */
void IntNode::InsertAfter(IntNode* nodeLoc) {
   IntNode* tmpNext = 0;

   tmpNext = this->nextNodePtr;    // Remember next
   this->nextNodePtr = nodeLoc;    // this -- node -- ?
   nodeLoc->nextNodePtr = tmpNext; // this -- node -- next
   return;
}

// Grab location pointed by nextNodePtr
IntNode* IntNode::GetNext() {
   return this->nextNodePtr;
}

int IntNode::GetDataVal() {
   return this->dataVal;
}

int main() {
   IntNode* headObj = 0; // Create intNode objects
   IntNode* currObj = 0;
   IntNode* lastObj = 0;
   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
      currObj = new IntNode((rand() % 21) - 10);
      lastObj->InsertAfter(currObj); // Append curr
      lastObj = currObj;             // Curr is the new last item
   }

   currObj = headObj;                // Print the list
   while (currObj != 0) {
      cout << currObj->GetDataVal() << ", ";
      currObj = currObj->GetNext();
   }
   cout << endl;

   currObj = headObj;                // Count number of negative numbers
   while (currObj != 0) {

      /* Your solution goes here  */
   
      negativeCntr = currObj->GetDataVal();
      
      currObj = currObj->GetNext();
   }
   cout << "Number of negatives: " << negativeCntr << endl;

   return 0;

Testing with 6 negatives
Expected output: Number of negatives: 6
Your output: Number of negatives: -8

 

[squidsk]

If you're supposed to be counting the number of negatives, where's your code that is doing the counting?

 

[Teh]

If you're supposed to be counting the number of negatives, where's your code that is doing the counting?

This is my code for counting the number of negatives but I am not sure if it it right.

negativeCntr = currObj->GetDataVal();

 

[squidsk]

If that code is supposed to count (i.e. do addition) I think you're missing something critical on the line. Also if you're supposed to count only the negative numbers you need to figure out whether the number at that spot in the linked list is negative. Two other questions for you to ponder. First how does your output relate to the contents of the list (make changes to the list to get a better sense of this). Two what does the function GetDataVal return and what are you currently expecting it to return.