Implement Stack Using Array with Push and Pop Operations

Code

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

#define MAX 10

void process_stack(int n) {
    int stack[MAX];
    int top = -1;

    char line[20];
    for (int i = 0; i < n; i++) {
        fgets(line, sizeof(line), stdin);

        if (strncmp(line, "push", 4) == 0) {
            int x;
            sscanf(line + 5, "%d", &x);  // Read value after "push "
            if (top + 1 >= MAX) {
                printf("Stack Overflow\n");
            } else {
                top++;
                stack[top] = x;
            }
        } else if (strncmp(line, "pop", 3) == 0) {
            if (top < 0) {
                printf("Stack Underflow\n");
            } else {
                printf("%d\n", stack[top]);
                top--;
            }
        }
    }
}

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

    process_stack(n);
    return 0;
}

Solving Approach

• Implement a stack using a fixed-size array
• Support 2 operations:
   
  • push x → Push value x into the stack
  • pop → Pop and print the top value from the stack
• Print "Stack Overflow" if trying to push when full
• Print "Stack Underflow" if trying to pop when empty