linkedListFuncs.cpp

#include <iostream>
#include <string>
#include <sstream> // for ostringstream
#include <cassert>

#include "linkedList.h"
#include "linkedListFuncs.h"

LinkedList * arrayToLinkedList(int *a, int size) {
  
  LinkedList * list = new LinkedList;

  list->head=NULL; 
  list->tail=NULL;

  for (int i=0; i<size; i++) {
    // add array[i] to the list

    if ( list->head==NULL) {
      list->head = new Node;
      list->head->data = a[i]; // (*head).data = a[i];
      list->head->next = NULL;
      list->tail = list->head;
    } else {
      list->tail->next = new Node;
      list->tail = list->tail->next;
      list->tail->next = NULL;
      list->tail->data = a[i];
    }
  }

  return list; // return ptr to new list

}

// intToString converts an int to a string

std::string intToString(int i) {
// creates a stream like cout, cerr that writes to a string
  std::ostringstream oss; 
  oss << i;
  return oss.str(); // return the string result
}

std::string arrayToString(int a[], int size) {

  std::ostringstream oss;
  // fencepost problem; first element gets no comma in front
  oss << "{"; 

  if (size>0)
    oss << intToString(a[0]); 

  for (int i=1; i<size; i++) {
    oss << "," << intToString(a[i]);
  }
  oss << "}";

  return oss.str();
  
}


// free up every node on this linked list
// nice clean code thanks to @sashavolv2 (on Twitter) #woot

void freeLinkedList(LinkedList * list) {

  Node *next;

  for (Node *p=list->head; p!=NULL; p=next) {
    next = p->next;
    delete p;
  }

  delete list; // returns memory to the heap
}

std::string linkedListToString(LinkedList *list) {

  std::string result="";
  for (const Node *  p=list->head; p!=NULL; p=p->next) {
    result += "[" + intToString(p->data) + "]->";
  }
  result += "null";
  return result;
}