stack

#include <stdio.h>
#define stack_max 10

//structure variable
typedef struct{
    int top;
    int data[stack_max];
}stack;

//push function
void push(stack *s, int item)
{
    if(s->top < stack_max){
        s->data[s->top] = item;
        s->top++;//when, pushing will be done the value of top will be one more than the length of the array
        //so in the pop function first decrease one from top to excess the array
    }
    else{
        printf("stack is full!!\n");
    }
    //printf("%d\n", s->top);
}

//pop function
int pop(stack *s)
{
    int item;
    if(s->top == 0){
        printf("Stack is empty\n");
        return -1;
    }
    else{
    //decreasing top value one
    s->top--;
    item = s->data[s->top];
    }
    return item;
}

int main()
{
    stack my_stack;
    int item;
    my_stack.top = 0;
    //calling push function
    push(&my_stack, 1);
    //printf("%d\n", my_stack.top);
    push(&my_stack, 2);
    //printf("%d\n", my_stack.top);
    push(&my_stack, 3);
    //printf("%d\n", my_stack.top);

    //calling pop function
    item = pop(&my_stack);
    printf("%d\n", item);
    item = pop(&my_stack);
    printf("%d\n", item);
    item = pop(&my_stack);
    printf("%d\n", item);
    /*item = pop(&my_stack);
    printf("%d\n", item);*/
    return 0;
}