Algorithm-Collection/Data Structures/Stack/stack.c at master · bringani/Algorithm-Collection · GitHub

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#include<stdio.h>
#include<stdlib.h>

//self referencing structure with one data element
structNode {
intdata;
structNode*next;
};

// Aliasing for easier referencing
typedefstructNodeNode;

/*-------------------------------------- Stack Functions -------------------------------------- */
/** Ideally these should go in a seperate Header file (ie. stack.h) along with the self referencing structure
 *
 * Stack Functions
 * Create Node : create_node
 * Push : push (adds an item to the top of the stack)
 * Pop : pop (removes the topmost item from the stack)
 * Peek : peek (take a look at the topmost item without popping)
 * Display Stack : print_stack
 *
 */

Node*create_node(intdata) {
Node*new_node=malloc(1*sizeof(Node));

new_node->data=data;
new_node->next=NULL;

returnnew_node;
}


// adds a Node to the top of the stack
voidpush(Node**top, intdata) {
Node*new_node=create_node(data);

if(*top!=NULL) {
new_node->next=*top;
 }

*top=new_node;

}

// Pops the Top Node from the Stack
intpop(Node**top) {
if(*top==NULL) {
printf("Popping Failed: Empty Stack !!\n");
return-1;
 }

Node*popped=*top;

*top=popped->next;

intpopped_int=popped->data;

free(popped);

printf("Successfully Popped : %d\n", popped_int);

returnpopped_int;
}

// Prints all the elements in the Stack
voidprint_stack(Node*top) {
if(top==NULL) {
printf("Empty Stack!!\n");
return;
 }

printf("[");

while(top!=NULL) {
printf(" %d", top->data);

if(top->next!=NULL) printf(",");

top=top->next;
 }

printf(" ]\n");
}

//Prints the topmost item in the Stack
voidpeek(Node*top) {
if(top==NULL) {
printf("Empty Stack!!\n");
 }else {
printf("First item of the Stack : %d\n", top->data);
 }
}

/* --------------------------------- End of Stack Functions ----------------------------------- */

intmain() {
Node*stack=NULL;

push(&stack,10);
push(&stack,20);
push(&stack,50);

pop(&stack);
peek(stack);

push(&stack,40);
push(&stack,80);

print_stack(stack);

}