C code

#define MAX_SIZE 100

int stack[MAX_SIZE];
int top = -1;

void push(int value) {
    if (top == MAX_SIZE - 1) {
        printf("Error: Stack overflow\n");
        return;
    }
    top++;
    stack[top] = value;
}

int pop() {
    if (top == -1) {
        printf("Error: Stack underflow\n");
        return -1;
    }
    int value = stack[top];
    top--;
    return value;
}

int top() {
    if (top == -1) {
        printf("Error: Stack is empty\n");
        return -1;
    }
    return stack[top];
}

bool is_empty() {
    return top == -1;
}