#62 from KoulickS/master

Author: codewithdev

Interview Problems/02- LinkedList/Union_and_Intersection_of_Linkedlist_Amazon_Microsoft.cpp

@@ -0,0 +1,146 @@
+// C/C++ program to find union 
+// and intersection of two unsorted 
+// linked lists 
+#include <stdbool.h> 
+#include <stdio.h> 
+#include <stdlib.h> 
+/* Link list node */
+struct Node { 
+	int data; 
+	struct Node* next; 
+}; 
+
+/* A utility function to insert a 
+node at the beginning ofa linked list*/
+void push(struct Node** head_ref, int new_data); 
+
+/* A utility function to check if 
+given data is present in a list */
+bool isPresent(struct Node* head, int data); 
+
+/* Function to get union of two 
+linked lists head1 and head2 */
+struct Node* getUnion( 
+	struct Node* head1, 
+	struct Node* head2) 
+{ 
+	struct Node* result = NULL; 
+	struct Node *t1 = head1, *t2 = head2; 
+
+	// Insert all elements of 
+	// list1 to the result list 
+	while (t1 != NULL) { 
+		push(&result, t1->data); 
+		t1 = t1->next; 
+	} 
+
+	// Insert those elements of list2 
+	// which are not present in result list 
+	while (t2 != NULL) { 
+		if (!isPresent(result, t2->data)) 
+			push(&result, t2->data); 
+		t2 = t2->next; 
+	} 
+
+	return result; 
+} 
+
+/* Function to get intersection of 
+two linked lists head1 and head2 */
+struct Node* getIntersection(struct Node* head1, 
+							struct Node* head2) 
+{ 
+	struct Node* result = NULL; 
+	struct Node* t1 = head1; 
+
+	// Traverse list1 and search each element of it in 
+	// list2. If the element is present in list 2, then 
+	// insert the element to result 
+	while (t1 != NULL) { 
+		if (isPresent(head2, t1->data)) 
+			push(&result, t1->data); 
+		t1 = t1->next; 
+	} 
+
+	return result; 
+} 
+
+/* A utility function to insert a 
+node at the beginning of a linked list*/
+void push(struct Node** head_ref, int new_data) 
+{ 
+	/* allocate node */
+	struct Node* new_node 
+		= (struct Node*)malloc( 
+			sizeof(struct Node)); 
+
+	/* put in the data */
+	new_node->data = new_data; 
+
+	/* link the old list off the new node */
+	new_node->next = (*head_ref); 
+
+	/* move the head to point to the new node */
+	(*head_ref) = new_node; 
+} 
+
+/* A utility function to print a linked list*/
+void printList(struct Node* node) 
+{ 
+	while (node != NULL) { 
+		printf("%d ", node->data); 
+		node = node->next; 
+	} 
+} 
+
+/* A utility function that returns true if data is 
+present in linked list else return false */
+bool isPresent(struct Node* head, int data) 
+{ 
+	struct Node* t = head; 
+	while (t != NULL) { 
+		if (t->data == data) 
+			return 1; 
+		t = t->next; 
+	} 
+	return 0; 
+} 
+
+/* Driver program to test above function*/
+int main() 
+{ 
+	/* Start with the empty list */
+	struct Node* head1 = NULL; 
+	struct Node* head2 = NULL; 
+	struct Node* intersecn = NULL; 
+	struct Node* unin = NULL; 
+
+	/*create a linked lits 10->15->5->20 */
+	push(&head1, 20); 
+	push(&head1, 4); 
+	push(&head1, 15); 
+	push(&head1, 10); 
+
+	/*create a linked lits 8->4->2->10 */
+	push(&head2, 10); 
+	push(&head2, 2); 
+	push(&head2, 4); 
+	push(&head2, 8); 
+
+	intersecn = getIntersection(head1, head2); 
+	unin = getUnion(head1, head2); 
+
+	printf("\n First list is \n"); 
+	printList(head1); 
+
+	printf("\n Second list is \n"); 
+	printList(head2); 
+
+	printf("\n Intersection list is \n"); 
+	printList(intersecn); 
+
+	printf("\n Union list is \n"); 
+	printList(unin); 
+
+	return 0; 
+}