Implement Stack Using Array with Push and Pop Operations

Code

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

#define MAX 10

typedef struct {
    int buffer[MAX];
    int head;
    int capacity;
} Stack;

void process_stack(int n) {
    char cmd[20] = {0};
    int data;
    Stack stk = {0};
    stk.capacity = n;

    while (n--) {
        scanf("%s %d\n", cmd, &data);
        if (!strncmp(cmd, "push", 4)) {
            if (stk.head > (MAX - 1)) {
                printf("Stack Overflow\n");
            } else {
                stk.buffer[stk.head++] = data;
            }
        } else if (!strncmp(cmd, "pop", 3)) {
            if ((stk.head - 1) < 0) {
                printf("Stack Underflow\n");
            } else {
                printf("%d\n", stk.buffer[--stk.head]);
            }
        }
    }
}

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

    process_stack(n);
    return 0;
}

Solving Approach