data-structures Stack Stack Implementation by using array and Linked List

Example

Array Implementation

#include<stdio.h>

#define MAX 100000                    //Global variables
int top = -1;
int a[MAX];

void push(int x){
    
    if(top == MAX-1){                         // Check whether stack is full
        printf("Stack Overflow\n");
        return;
    }
    
    a[++top] = x;                            // Otherwise increment top and insert x
}

void pop(){
    if(top == -1){                                     // if top = -1, empty stack
        printf("Empty stack\n");
        return;
    }
    top--;        
}

void print(){                         //printing stack values
    
    for(int i=0;i <= top;i++){
        printf("%d ",a[i]);        
    }        
    printf("\n");        
}

void topValue(){                        // Method can print the top value of a stack
    printf("%d",a[top]);
}
int main(){
        
    push(5);
    push(20);
    push(15);
    print();
    pop();
    print();
    push(35);
    print();
    topValue();    
    
}

Linked List implementation

#include<stdio.h>
#include<malloc.h>

 struct node{
    int data;
    node* link;
};
node* top = NULL;

void push(int data){
    
    node* temp = (struct node*)malloc(sizeof(struct node*));
    temp->data = data;
    temp->link = top;
    top = temp;
}

void pop(){
    
    if(top == NULL) return;
    node* temp = top;
    top = top->link;
    free(temp);
}
void print(){
    
    node* t = top;
    while(t != NULL){
        printf("%d ",t->data);
        t=t->link;
    }
    printf("\n");
}

void topValue(){
    printf("%d ",top->data);
}
int main(){
        
    push(5);
    push(20);
    push(15);
    print();
    pop();
    print();
    push(35);
    print();            
    topValue();    
}