p05_menu.c

#include <stdio.h>
#include <stdlib.h>

void show_menu();
int *read_array(int *);
void print_array(int *, int);
int biggest_odd(int *, int);
int smallest_even(int *, int);

int main()
{
    int size;
    int *arr;
    while (1)
    {
        show_menu();
        int choice;
        scanf("%d", &choice);
        if (choice == 1)
        {
            arr = read_array(&size);
        }
        else if (choice == 2)
        {
            print_array(arr, size);
        }
        else if (choice == 3)
        {
            printf("The biggest odd number is: %d\n", biggest_odd(arr, size));
        }
        else if (choice == 4)
        {
            printf("The smallest even number is: %d\n", smallest_even(arr, size));
        }
        else if (choice == 5)
        {
            return 0;
        }
        else
        {
            printf("Invalid input!\n\n");
        }
    }
    return 0;
}

void show_menu()
{
    printf("1. Read an array\n");
    printf("2. Print array\n");
    printf("3. Get largest odd number\n");
    printf("4. Get smallest even number\n");
    printf("5. Exit\n");
    printf("Choose your option: ");
}

int *read_array(int *size)
{
    *size = 1;
    int *arr;
    int arr_size = 10;
    arr = (int *)malloc(arr_size * sizeof(int));

    printf("Enter value of element at index %d (EOF to stop input): ", *size - 1);
    while (scanf("%d", &arr[*size - 1]) == 1)
    {
        getchar();
        *size = *size + 1;
        if (*size > arr_size)
        {
            arr_size += 10;
            arr = realloc(arr, arr_size * sizeof(int));
        }

        printf("Enter value of element at index %d (EOF to stop input): ", *size - 1);
    }

    printf("\n");
    *size = *size - 1;
    return arr;
}

void print_array(int *array, int size)
{
    printf("[");
    for (int i = 0; i < size; i++)
    {
        printf("%d", array[i]);
        if (i != size - 1)
            printf(", ");
    }

    printf("]\n");
}

int biggest_odd(int *arr, int size)
{
    int max = arr[0];
    for (int i = 0; i < size; i++)
    {
        if(arr[i] > max) {
            if(arr[i] % 2 == 1) max = arr[i];
        }
    }

    return max;
}

int smallest_even(int *arr, int size)
{
    int min = arr[0];
    for (int i = 0; i < size; i++)
    {
        if(arr[i] < min) {
            if(arr[i] % 2 == 0) min = arr[i];
        }
    }

    return min;
}