HackerRank-Printing Frequency of digits in Number (C language)

Printing the frequency of digits (0 to 9). 

 #include <stdio.h>

#include <string.h>

#include <math.h>

#include <stdlib.h>

int main() {

    char str[1000];

    scanf("%s" , str);

    int arr[10] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

    int i = 0;

    while (str[i] != '\0')

    {

        if (str[i] == '0' || str[i] == '1' || str[i] == '2' || str[i] == '3' ||

            str[i] == '4' || str[i] == '5' ||

            str[i] == '6' || str[i] == '7' || str[i] == '8' || str[i] == '9')

        {

            arr[str[i] - '0']++;

        }

        i++;

    }

    for (int i = 0; i < 10; i++)

    {

        printf("%d " , arr[i]);

    }

    return 0;

}