Update DS/C/Lab/Week7/linkedlist.c

DS/C/Lab/Week7/linkedlist.c

@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h>
 
 typedef struct Node
 {
@@ -6,6 +7,82 @@ typedef struct Node
     struct Node *next;
 } Node;
 
+// case 1
+Node *insBef(Node *head, int newData, int targetData)
+{
+    Node *temp = (Node *)malloc(sizeof(Node));
+    temp->data = newData;
+    temp->next = NULL;
+
+    if (head == NULL)
+    {
+        printf("List is empty. Inserting as the first element.\n");
+        return temp;
+    }
+
+    if (head->data == targetData)
+    {
+        temp->next = head;
+        return temp;
+    }
+
+    Node *current = head;
+    Node *prev = NULL;
+
+    while (current != NULL && current->data != targetData)
+    {
+        prev = current;
+        current = current->next;
+    }
+
+    if (current == NULL)
+    {
+        printf("Target element not found. Insertion failed.\n");
+        free(temp);
+        return head;
+    }
+
+    prev->next = temp;
+    temp->next = current;
+
+    printf("Element inserted successfully.\n");
+    return head;
+}
+
+// case 2
+Node *insAft(Node *head, int newData, int targetData)
+{
+    Node *temp = (Node *)malloc(sizeof(Node));
+    temp->data = newData;
+    temp->next = NULL;
+
+    if (head == NULL)
+    {
+        printf("List is empty. Inserting as the first element.\n");
+        return temp;
+    }
+
+    Node *current = head;
+
+    while (current != NULL && current->data != targetData)
+    {
+        current = current->next;
+    }
+
+    if (current == NULL)
+    {
+        printf("Target element not found. Insertion failed.\n");
+        free(temp);
+        return head;
+    }
+
+    temp->next = current->next;
+    current->next = temp;
+
+    printf("Element inserted successfully.\n");
+    return head;
+}
+
 // case 3
 Node *delEle(Node *head, int data)
 {
@@ -57,14 +134,108 @@ void dispList(Node *head)
     printf("\n");
 }
 
+// case 5
+Node *revList(Node *head)
+{
+    Node *prev = NULL;
+    Node *current = head;
+    Node *next = NULL;
+
+    while (current != NULL)
+    {
+        next = current->next;
+        current->next = prev;
+        prev = current;
+        current = next;
+    }
+
+    head = prev;
+    printf("List reversed successfully.\n");
+    return head;
+}
+
+// case 6
+Node *sortList(Node *head)
+{
+    if (head == NULL || head->next == NULL)
+        return head;
+
+    Node *current, *index;
+    int temp;
+
+    for (current = head; current->next != NULL; current = current->next)
+    {
+        for (index = current->next; index != NULL; index = index->next)
+        {
+            if (current->data > index->data)
+            {
+                temp = current->data;
+                current->data = index->data;
+                index->data = temp;
+            }
+        }
+    }
+
+    printf("List sorted successfully.\n");
+    return head;
+}
+
+// case 7
+Node *delAltNode(Node *head)
+{
+    if (head == NULL || head->next == NULL)
+        return head;
+
+    Node *current = head;
+    Node *temp;
+
+    while (current != NULL && current->next != NULL)
+    {
+        temp = current->next;
+        current->next = temp->next;
+        free(temp);
+        current = current->next;
+    }
+
+    printf("Alternate nodes deleted successfully.\n");
+    return head;
+}
+
+// case 8
+Node *enterSortList(Node *head, int data)
+{
+    Node *temp = (Node *)malloc(sizeof(Node));
+    temp->data = data;
+    temp->next = NULL;
+
+    if (head == NULL || head->data >= temp->data)
+    {
+        temp->next = head;
+        head = temp;
+    }
+    else
+    {
+        Node *current = head;
+        while (current->next != NULL && current->next->data < temp->data)
+        {
+            current = current->next;
+        }
+        temp->next = current->next;
+        current->next = temp;
+    }
+
+    printf("Element inserted in sorted list successfully.\n");
+    return head;
+}
+
 int main()
 {
     Node *head = NULL;
-    int choice, data;
+    int choice, data, data1;
     while (1)
     {
         printf("Choose the Linked List Operation you would like to perform:\n");
-        printf("1. Insert element BEFORE another element\n2. Insert element AFTER another element\n3. Delete a given element from the list\n4. Traverse the list\n5. Reverse the list\n6. Sort the list\n7. Delete every alternate node in the list\n7. Insert an element in a sorted list\n");
+        printf("1. Insert element BEFORE another element\n2. Insert element AFTER another element\n3. Delete a given element from the list\n4. Traverse the list\n5. Reverse the list\n6. Sort the list\n7. Delete every alternate node in the list\n8. Insert an element in a sorted list\n");
         scanf("%d", &choice);
 
         switch (choice)
@@ -74,40 +245,45 @@ int main()
             scanf("%d", &data);
             printf("Enter the number BEFORE which you would like to insert it: ");
             scanf("%d", &data1);
-            insBef(data, data1);
+            head = insBef(head, data, data1);
             break;
         case 2:
             printf("Enter the value for the latest element: ");
             scanf("%d", &data);
             printf("Enter the number AFTER which you would like to insert it: ");
             scanf("%d", &data1);
-            insAft(data, data1);
+            head = insAft(head, data, data1);
             break;
         case 3:
             printf("Enter the element you want to delete: ");
             scanf("%d", &data);
-            delEle(data);
+            head = delEle(head, data);
             break;
         case 4:
-            printf("List traversal");
+            printf("List traversal\n");
             dispList(head);
             break;
         case 5:
+            head = revList(head);
             printf("The reversed link list is: ");
-            revList();
+            dispList(head);
             break;
         case 6:
+            head = sortList(head);
             printf("The sorted list is: ");
-            sortList();
+            dispList(head);
             break;
         case 7:
-            printf("The list after deleting every alternate node is:");
+            head = delAltNode(head);
-            delAltNode();
+            printf("The list after deleting every alternate node is: ");
+            dispList(head);
             break;
         case 8:
             printf("Enter the element you want to insert: ");
             scanf("%d", &data);
-            enterSortList(data);
+            head = enterSortList(head, data);
+            printf("The updated sorted list is: ");
+            dispList(head);
             break;
         }
     }