Delete duplicates in a linked list
/*
* DeleteDupsLinkedList.cpp
*
* Created on: Apr 14, 2012
* Author: Kiran Hegde
*/
#include <iostream>
#include <cstdlib>
#include <time.h>
using namespace std;
struct Node {
int data;
Node *next;
};
/**
* Generate a linked list of length "size" containing random numbers from 0 to 9
*/
Node *createLinkedList(int size) {
srand(time(NULL));
Node *head = NULL;
for (int i = 0; i < size; i++) {
Node *node = new Node;
node->data = rand() % 10;
node->next = head;
head = node;
}
return head;
}
void deleteLinkedList(Node *head) {
while (head != NULL) {
Node *temp = head;
head = head->next;
delete temp;
}
}
void printLinkedList(Node *head) {
Node *curr = head;
while (curr != NULL) {
cout << curr->data << "-->";
curr = curr->next;
}
cout << "EMPTY" << endl;
}
/**
*
*/
void deleteDuplicateNodes(Node *head) {
Node *curr = head;
//step through the linked list
while (curr != NULL) {
Node *firstRunner = curr;
Node *secondRunner = curr->next;
// delete all subsequent nodes if they are duplicates
while (secondRunner != NULL) {
if (curr->data == secondRunner->data) { // duplicate
Node *temp = secondRunner;
firstRunner->next = secondRunner->next;
secondRunner = secondRunner->next;
delete temp;
}
else {
firstRunner = firstRunner->next;
secondRunner = secondRunner->next;
}
}
curr = curr->next;
}
}
/**
* Test the function
*/
int main() {
Node *head = createLinkedList(15);
cout << "Original List: ";
printLinkedList(head);
deleteDuplicateNodes(head);
cout << "After Deleting Dups: ";
printLinkedList(head);
deleteLinkedList(head);
return 0;
}