Stack using Linked List added

Author: me-shaon

Data Structure/Stack/README.md

@@ -25,11 +25,12 @@ To use a stack efficiently, we need to check the status of stack as well. For th
 - **isEmpty()** − check if stack is empty.
 
 
-####Complexity Analysis
+#### Complexity Analysis
 - Insertion - O(1)
 - Deletion - O(1)
 - Access - O(n)
 - Search - O(n)
+
 ### More on this topic
 - https://en.wikipedia.org/wiki/Stack_(abstract_data_type)
 - https://www.tutorialspoint.com/data_structures_algorithms/stack_algorithm.htm

Data Structure/Stack/stack_using_linked_list.c

@@ -0,0 +1,79 @@
+#include<stdio.h>
+#include<stdlib.h>
+
+typedef struct
+{
+    int val;
+	struct node* next;
+}node;
+
+node* top = NULL;
+
+void push(int value)
+{
+	node* tmp=(node*) malloc(sizeof(node)); //memory allocating for a node
+
+	tmp->val = value;
+	tmp->next = top; //add this new value at the end of the stack
+
+	top = tmp; //now top of the stack is the new node
+}
+
+void pop()
+{
+	node* tmp;
+
+	if(top==NULL)
+		printf("Stack is empty\n");
+	else
+	{
+		printf("popped element %d\n",top->val);
+		tmp=top;
+
+		top=top->next; //top is replaced to the next node
+
+		free(tmp); //top node is deleted from the memory
+	}
+}
+
+int peek()
+{
+    if(top != NULL)
+        return (int)top->val;
+
+    return top;
+}
+
+int main()
+{
+	int action,value;
+	int exit = 0;
+
+	while(!exit)
+	{
+	    printf("Enter Action: \n 1.Insert \n 2.Get Top Value \n 3.Exit\n");
+	    scanf("%d",&action);
+
+		switch(action)
+		{
+            case 1:
+                printf("Enter Value: ");
+                scanf("%d",&value);
+
+                push(value);
+
+                printf("Element at top of the stack: %d\n", peek());
+
+                break;
+            case 2:
+                pop();
+
+                break;
+            case 3:
+                exit = 1;
+                break;
+		}
+	}
+
+	return 0;
+}