stack_using_linked list

stack_using_linked list

@@ -0,0 +1,119 @@
+#include <stdio.h>  
+#include <stdlib.h>  
+void push();  
+void pop();  
+void display();  
+struct node   
+{  
+int val;  
+struct node *next;  
+};  
+struct node *head;  
+
+void main ()  
+{  
+    int choice=0;     
+    printf("\nStack operations using linked list ------\n");  
+
+    while(choice != 4)  
+    {  
+        printf("\n\nChose one from the below options...\n");  
+        printf("\n1.Push\n2.Pop\n3.Show\n4.Exit");  
+        printf("\n Enter your choice \n");        
+        scanf("%d",&choice);  
+        switch(choice)  
+        {  
+            case 1:  
+            {   
+                push();  
+                break;  
+            }  
+            case 2:  
+            {  
+                pop();  
+                break;  
+            }  
+            case 3:  
+            {  
+                display();  
+                break;  
+            }  
+            case 4:   
+            {  
+                printf("Exiting....");  
+                break;   
+            }  
+            default:  
+            {  
+                printf("Please Enter valid choice ");  
+            }   
+    };  
+}  
+}  
+void push ()  
+{  
+    int val;  
+    struct node *ptr = (struct node*)malloc(sizeof(struct node));   
+    if(ptr == NULL)  
+    {  
+        printf("not able to push the element");   
+    }  
+    else   
+    {  
+        printf("Enter the value");  
+        scanf("%d",&val);  
+        if(head==NULL)  
+        {         
+            ptr->val = val;  
+            ptr -> next = NULL;  
+            head=ptr;  
+        }   
+        else   
+        {  
+            ptr->val = val;  
+            ptr->next = head;  
+            head=ptr;  
+
+        }  
+        printf("Item pushed");  
+
+    }  
+}  
+
+void pop()  
+{  
+    int item;  
+    struct node *ptr;  
+    if (head == NULL)  
+    {  
+        printf("Underflow");  
+    }  
+    else  
+    {  
+        item = head->val;  
+        ptr = head;  
+        head = head->next;  
+        free(ptr);  
+        printf("Item popped");  
+
+    }  
+}  
+void display()  
+{  
+    int i;  
+    struct node *ptr;  
+    ptr=head;  
+    if(ptr == NULL)  
+    {  
+        printf("Stack is empty\n");  
+    }  
+    else  
+    {  
+        printf("Printing Stack elements \n");  
+        while(ptr!=NULL)  
+        {  
+            printf("%d\n",ptr->val);  
+            ptr = ptr->next;  
+        }  
+    }  
+}