Stack Using Linked List

Implementation of a stack using linked list and its functions.

Stack Node Structure :

struct Node {
int data;
struct Node *next;
};
​
struct Node *top = NULL;

Function to Check if Stack is Empty :

int isEmpty() {
return top == NULL;
}

Stack Push Function :

void push(int data) {
​
// Creating a new stack node
struct Node *newNode;
newNode = (struct Node *)malloc(sizeof(struct Node));
newNode -> data = data;
// Set the next to point to current top
newNode -> next = top;
// Update top
top = newNode;
​
}

Stack Pop Function :

int pop() {
​
if (isEmpty()) {
printf("Stack underflow !\n");
return -1;
}
struct Node *toDelete = top;
int poppedValue = top -> data;
top = top -> next;
free(toDelete);
return poppedValue;
​
}

Stack Peek Function :

int peek() {
return top -> data;
}

Stack Display Function :

void display() {
​
if (isEmpty()) {
printf("Stack is empty\n");
return;
}
struct Node *ptr = top;
while (ptr != NULL) {
printf("%d\t", ptr -> data);
ptr = ptr -> next;
}
printf("\n");
​
}
Contributed by Nitin Ranganath