Variadic functions in C.c

/*Varaible argument functions in C - ellipsis in function signature for variable number of args
  include stdarg.h to get the 3 macros va_list, va_start, va_arg
  va_list ptr - to create a ptr of the type va_list
  va_start(ptr,count) - to set the pointer to the beginning of the first argument of the list of variable arguments
  va_arg(ptr, int) - to consume the int arg pointed to by the pointer currently and then move ptr to next arg
*/

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

#define MIN_ELEMENT 1
#define MAX_ELEMENT 1000000
int  sum (int count,...) {
    va_list ptr;
    va_start(ptr,count);
    int i,num,sum=0;
    for(i=1;i<=count;i++)
    {
        num=va_arg(ptr,int);
        sum+=num;
    }
    return sum;
}

int min(int count,...) {
    va_list ptr;
    va_start(ptr,count);
    int i,num,min=MAX_ELEMENT;
    for(i=1;i<=count;i++)
    {
        num=va_arg(ptr,int);
        if(num<min) min=num;
    }
    return min;
}

int max(int count,...) {
    va_list ptr;
    va_start(ptr,count);
    int i,num,max=MIN_ELEMENT;
    for(i=1;i<=count;i++)
    {
        num=va_arg(ptr,int);
        if(num>max) max=num;
    }
    return max;
}

int test_implementations_by_sending_three_elements() {
    srand(time(NULL));
    
    int elements[3];
    
    elements[0] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[1] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[2] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    
    fprintf(stderr, "Sending following three elements:\n");
    for (int i = 0; i < 3; i++) {
        fprintf(stderr, "%d\n", elements[i]);
    }
    
    int elements_sum = sum(3, elements[0], elements[1], elements[2]);
    int minimum_element = min(3, elements[0], elements[1], elements[2]);
    int maximum_element = max(3, elements[0], elements[1], elements[2]);

    fprintf(stderr, "Your output is:\n");
    fprintf(stderr, "Elements sum is %d\n", elements_sum);
    fprintf(stderr, "Minimum element is %d\n", minimum_element);
    fprintf(stderr, "Maximum element is %d\n\n", maximum_element);
    
    int expected_elements_sum = 0;
    for (int i = 0; i < 3; i++) {
        if (elements[i] < minimum_element) {
            return 0;
        }
        
        if (elements[i] > maximum_element) {
            return 0;
        }
        
        expected_elements_sum += elements[i];
    }
    
    return elements_sum == expected_elements_sum;
}

int test_implementations_by_sending_five_elements() {
    srand(time(NULL));
    
    int elements[5];
    
    elements[0] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[1] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[2] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[3] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[4] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    
    fprintf(stderr, "Sending following five elements:\n");
    for (int i = 0; i < 5; i++) {
        fprintf(stderr, "%d\n", elements[i]);
    }
    
    int elements_sum = sum(5, elements[0], elements[1], elements[2], elements[3], elements[4]);
    int minimum_element = min(5, elements[0], elements[1], elements[2], elements[3], elements[4]);
    int maximum_element = max(5, elements[0], elements[1], elements[2], elements[3], elements[4]);
    
    fprintf(stderr, "Your output is:\n");
    fprintf(stderr, "Elements sum is %d\n", elements_sum);
    fprintf(stderr, "Minimum element is %d\n", minimum_element);
    fprintf(stderr, "Maximum element is %d\n\n", maximum_element);
    
    int expected_elements_sum = 0;
    for (int i = 0; i < 5; i++) {
        if (elements[i] < minimum_element) {
            return 0;
        }
        
        if (elements[i] > maximum_element) {
            return 0;
        }
        
        expected_elements_sum += elements[i];
    }
    
    return elements_sum == expected_elements_sum;
}

int test_implementations_by_sending_ten_elements() {
    srand(time(NULL));
    
    int elements[10];
    
    elements[0] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[1] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[2] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[3] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[4] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[5] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[6] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[7] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[8] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    elements[9] = rand() % (MAX_ELEMENT - MIN_ELEMENT + 1) + MIN_ELEMENT;
    
    fprintf(stderr, "Sending following ten elements:\n");
    for (int i = 0; i < 10; i++) {
        fprintf(stderr, "%d\n", elements[i]);
    }
    
    int elements_sum = sum(10, elements[0], elements[1], elements[2], elements[3], elements[4],
                           elements[5], elements[6], elements[7], elements[8], elements[9]);
    int minimum_element = min(10, elements[0], elements[1], elements[2], elements[3], elements[4],
                           elements[5], elements[6], elements[7], elements[8], elements[9]);
    int maximum_element = max(10, elements[0], elements[1], elements[2], elements[3], elements[4],
                           elements[5], elements[6], elements[7], elements[8], elements[9]);
    
    fprintf(stderr, "Your output is:\n");
    fprintf(stderr, "Elements sum is %d\n", elements_sum);
    fprintf(stderr, "Minimum element is %d\n", minimum_element);
    fprintf(stderr, "Maximum element is %d\n\n", maximum_element);
    
    int expected_elements_sum = 0;
    for (int i = 0; i < 10; i++) {
        if (elements[i] < minimum_element) {
            return 0;
        }
        
        if (elements[i] > maximum_element) {
            return 0;
        }
        
        expected_elements_sum += elements[i];
    }
    
    return elements_sum == expected_elements_sum;
}

int main ()
{
    int number_of_test_cases;
    scanf("%d", &number_of_test_cases);
    
    while (number_of_test_cases--) {
        if (test_implementations_by_sending_three_elements()) {
            printf("Correct Answer\n");
        } else {
            printf("Wrong Answer\n");
        }
        
        if (test_implementations_by_sending_five_elements()) {
            printf("Correct Answer\n");
        } else {
            printf("Wrong Answer\n");
        }
        
        if (test_implementations_by_sending_ten_elements()) {
            printf("Correct Answer\n");
        } else {
            printf("Wrong Answer\n");
        }
    }
    
    return 0;
}