Implement Stack Using Array with Push and Pop Operations

Code

#include <stdio.h>
#include <stdint.h>
#include <string.h>

#define MAX 10

typedef struct s 
{
  int a[MAX];
  int top;
  int capacity;
}stack;

void process_stack(int n) 
{
    stack s; //s is a variable of type:stack which is defined above.
    s.top=-1;
    s.capacity=10;

    char operation[8];
    char *ptr;
    while(n)
    {
      scanf(" %[^\n]",operation);  
      //logic for push operation.
      ptr=strstr(operation,"push");
      if(ptr!=NULL)
      {
        if(s.top==(s.capacity)-1) //Condition to check if stack is full.
        {
          printf("Stack Overflow\n");
        }
        else 
        {
          int val;
          ptr=strchr(operation,' ');
          sscanf(ptr+1,"%d",&val);
          //printf("DEBUG: val:%d\n",val);
          (s.top)++;
           s.a[s.top]=val;
           //printf("DEBUG: Element inserted last at %d position with val:%d\n",s.top,val);
        }
      }

      //logic for pop operation.
      ptr=strstr(operation,"pop");
      if(ptr!=NULL)
      {
        if(s.top==-1)  //condition to check if stack is empty.
        {
            printf("Stack Underflow\n");
        }
        else 
        {
            printf("%d\n",s.a[s.top]);
          (s.top)--;
        }
      }

      n--;
    }
}

int main() {
    int n;
    scanf("%d", &n);
    getchar(); // Consume newline after number

    process_stack(n);
    return 0;
}

Solving Approach