Three smallest elements in the array of integers.c

// Find three smallest elements in the array of integers without sorting array
// https://www.geeksforgeeks.org/find-the-largest-three-elements-in-an-array/
// This code is edited by Ayush Singla(@ayusin51) and Dragan Milicev (dmilicev@gmail.com)

#include <stdio.h>
#include <limits.h> // For INT_MAX

// Function to print array
void ShowArray(char text[],int arr[],int n)
{
    int i;

    printf("\n%s",text);
    for(i=0;i<n;i++)
        printf("%5d", arr[i]);

    printf("\n");
}

// Function to print three smallest elements
void print3smallest(int arr[], int arr_size)
{
    int i, first, second, third;

    if (arr_size < 3)
    {
        printf("\n Invalid input. There should be atleast three elements in array. \n");
        return;
    }

// 1) Initialize the smallest three elements as plus infinite.
//    first = second = third = +Infinity

    first = second = third = INT_MAX;

    printf("\n How algorithm work: \n");
    printf("\n  i  arr[i]       first     second        third \n"); // header

// 2) Iterate through all elements of array.

    for (i = 0; i < arr_size ; i ++)
    {
        if (arr[i] < first)         // Let current array element be arr[i]
        {                           // If current element is smaller than first
            third = second;         // then update third, second and first
            second = first;         // This order of assignment is important
            first = arr[i];
        }
        else if (arr[i] < second)   // If arr[i] is in between first and second
        {                           // then update second
            third = second;
            second = arr[i];
        }
        else if (arr[i] < third)    // If arr[i] smaller then third
            third = arr[i];         // then update third

        // print how algorithm work
        printf("\n %2d  %4d %12d  %12d  %12d \n",i,arr[i],first,second,third);
    }

// 3) Print first, second and third.

    printf("\n Three smallest elements are: %3d %3d %3d \n", first, second, third);
}


// Driver program to test above function
int main(void)
{
    int arr[] = {12, 13, 1, 10, 34, 2};     // try different one
//  int arr[]={9,2,7,7,8,6,5,1,3};
//  int arr[]={7,2,7,7,8,6,5,1,3};
//  int arr[]={4,2,9,7,8,6,5,1,9};
//  int arr[] = {1,1,1,1,1,1};
//  int arr[] = {1,1};
    int n = sizeof(arr)/sizeof(arr[0]);     // a way to get n, number of elements in array
    int i;

    printf(" n = %d \n", n);            // print number of elements in array

    ShowArray(" Array is: ",arr,n);

    print3smallest(arr, n);                 // print three smallest elements in the array

    return 0;
}