chore: Updated the coding structure for more readability.

data_structures/linked_list/ascending_priority_queue.c

@@ -24,43 +24,39 @@ delete() -  Would delete the smallest element in the queue
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <limits.h>
 #define NULL ((void *)0)
 
-struct node
+typedef struct node
 {
     int data;
     struct node *next;
-};
+}node;
 
-struct node *front, *rear;
+node *front, *rear;
 
 /* This function initializes the queue to empty by making both front and rear as
  * NULL */
 void createqueue() { front = rear = NULL; }
 
-int empty()
+int isempty()
 {
-    if (front == NULL)
-        return 1;
-    else
-        return 0;
+    return front == NULL;
 }
 
-void insert(int x)
+void insert(int data)
 {
-    struct node *pnode;
-
-    pnode = (struct node *)malloc(sizeof(struct node));
+    node *pnode = (node *)malloc(sizeof(node));
     if (pnode == NULL)
     {
         printf("Memory overflow. Unable to insert.\n");
         exit(1);
     }
 
-    pnode->data = x;
+    pnode->data = data;
     pnode->next = NULL; /* New node is always last node */
 
-    if (empty())
+    if (isempty())
         front = rear = pnode;
     else
     {
@@ -71,72 +67,70 @@ void insert(int x)
 
 int removes()
 {
-    int min;
-    struct node *follow, *follow1, *p, *p1;
 
-    if (empty())
+    node *follow, *follow1, *temp, *target_node;
+
+    if (isempty())
     {
         printf("\nQueue Underflow. Unable to remove.");
         exit(1);
     }
 
     /* finding the node with minimum value in the APQ.*/
-    p = p1 = front;
     follow = follow1 = NULL;
-    min = front->data;
-    while (p != NULL)
-    {
-        if (p->data < min)
+    int min = front->data;
+    for(temp = target_node = front; temp!=NULL; temp=temp->next){
+    if (temp->data < min)
         {
-            min = p->data;
+            min = temp->data;
             follow1 = follow;
-            p1 = p;
+            target_node = temp;
         }
-        follow = p;
-        p = p->next;
+        follow = temp;
     }
-
+   
     /* Deleting the node with min value */
 
-    if (p1 == front) /* deleting first node.*/
+    if (target_node == front) /* deleting first node.*/
     {
         front = front->next;
         if (front == NULL) /* Deleting the only one node */
             rear = NULL;
     }
-    else if (p1 == rear) /* Deleting last node */
+    else if (target_node == rear) /* Deleting last node */
     {
         rear = follow1;
         rear->next = NULL;
     }
     else /* deleting any other node.*/
-        follow1->next = p1->next;
+        follow1->next = target_node->next;
 
-    free(p1);
+    free(target_node);
     return min; /* DONT FORGET LAST 2 STATEMENTS.*/
 }
 
 void show()
 {
-    struct node *p;
-
-    if (empty())
+    if (isempty())
         printf("Queue empty. No data to display \n");
     else
     {
         printf("Queue from front to rear is as shown: \n");
 
-        p = front;
-        while (p != NULL)
-        {
-            printf("%d ", p->data);
-            p = p->next;
-        }
+        for(node *temp = front; temp!=NULL; temp=temp->next)
+            printf("%d ", temp->data);
 
         printf("\n");
     }
 }
 
+void menu()
+{
+    printf("\n\n  Menu: \n");
+    printf("1:Insert \n");
+    printf("2:Remove \n");
+    printf("3:exit \n");
+}
 void destroyqueue() { front = rear = NULL; }
 
 int main()
@@ -147,12 +141,10 @@ int main()
 
     do
     {
-        printf("\n\n  Menu: \n");
-        printf("1:Insert \n");
-        printf("2:Remove \n");
-        printf("3:exit \n");
+        menu();
         printf("Enter your choice: ");
         scanf("%d", &ch);
+
 
         switch (ch)
         {
@@ -171,6 +163,9 @@ int main()
 
         case 3:
             break;
+        default:
+            printf("Enter valid case\n");
+            break;
         }
     } while (ch != 3);